CN103472487A - Transient-electromagnetic multi-component advanced detecting method and device - Google Patents

Abstract

The invention relates to a transient electromagnetic multi-component advanced detection method and device for a roadway excavation working face. It includes three detection wire frames, and each detection wire frame is arranged crosswise at a certain angle, and the detection wire frames arranged at different angles are used to collect transient electromagnetic data in three directions. The invention adopts a multi-channel transient electromagnetic instrument, arranges three components of transmitting and receiving wire frames according to the center loop device, and realizes the three-component data acquisition of the advance detection of the roadway excavation working face. Multiple groups of test electrical parameter profiles can be obtained in one detection, which facilitates the interpretation and analysis of the geological conditions of multi-directional rock and coal seams in the detection space, improves the spatial positioning ability of the transient electromagnetic method in detecting low-resistivity abnormal areas, and provides more safety for roadway excavation. Valid technical parameters.

Description

A transient electromagnetic multi-component advanced detection method and device

technical field

The invention relates to a transient electromagnetic method advanced detection method and a device system of a roadway excavation working face.

Background technique

Transient electromagnetic method, as a convenient and fast water detection method, has been widely used in the advance detection of roadway excavation working face. At present, a single component of the central vertical magnetic field is mostly used for data collection, that is, the horizontal component data is collected along the direction of the survey line according to the site conditions during construction, and the angle between the normal line of the wire frame and the survey line is adjusted according to the test requirements to complete the roof, bedding and floor. Probe in different directions, and then move the measuring point to complete the test of the entire excavation face. There are two problems in the application, one is that the angle of the single-point test line frame has been adjusted multiple times, and the construction process is more cumbersome; the other is that in the exploration of complex geological structures, conventional data acquisition technology is not conducive to collecting multi-directional geological body induction fields information. Therefore, the amount of single-point data collection is small, the exploration accuracy is low, and the level of geological interpretation is difficult to improve.

Through the improvement of the transient electromagnetic testing method, instrument channel structure, wire frame device system and data processing technology, the present invention obtains a set of transient electromagnetic multi-component advanced detection method and device system for roadway excavation working face, which can be used for advanced detection of roadway excavation Provide more comprehensive technical parameters.

Contents of the invention

The technical problem to be solved by the present invention is to provide a transient electromagnetic multi-component advanced detection method and device to accurately detect water-bearing geological anomalies in front of the roadway excavation working face.

In order to solve the above technical problems, the present invention provides a transient electromagnetic multi-component advanced detection device, which includes three detection wire frames, each detection wire frame is arranged at a certain angle, and the detection wire frames arranged at different angles are used to collect three Direction of transient electromagnetic data.

Preferably, the three detection wire frames have the same horizontal axis and are arranged crosswise at a certain angle, and the three detection wire frames respectively detect the transient electromagnetic data in the three directions of the roof, bedding and floor in front of the excavation working face.

Preferably, two pairs of the three detection wireframes are orthogonal to each other, and the transient induction field data in three directions are respectively collected.

Preferably, the detection wire frame includes a transmission wire frame and a reception wire frame, and when the transmission wire frame and the reception wire frame are arranged separately in the form of a center loop, the distance between the transmission wire frame and the reception wire frame is 0.8-1.2m.

Further preferably, the transmitting wire frame has 8-12 turns of cables and a side length of 1.8-2.2m, and the receiving wire frame has 18-22 turns of cables and a side length of 1.6-2.0m.

The three detection wire frames are respectively embedded in the soft panel, and the soft panel can be folded, which is convenient for carrying and operation.

The present invention also provides a detection method based on the above-mentioned transient electromagnetic multi-component advanced detection device, comprising the following steps:

Adjust the three detection wireframes to the required angles and fix them, and place them at the first measurement point.

Among the three detection wireframes, the transmission wireframe of one detection wireframe emits electromagnetic pulses, and its receiving wireframe receives transient electromagnetic data, or the three receiving wireframes are activated to receive transient electromagnetic data at the same time; or

The three detection wireframes transmit and receive transient electromagnetic data in turn.

After completing the data collection of a measurement point, move the distance of the measurement point according to the interval of 0.2-0.5m, and then collect the data at the next point until the data collection of the entire test section is completed.

Advantages of the present invention:

1. The transmitting and receiving wireframe realizes the excitation and reception of multiple components, simultaneously emits and observes the three components in the set direction, reduces the error caused by the angle adjustment of the wireframe when the measuring point is arranged, improves the amount of information obtained, and is beneficial to Collect multi-directional geological body sensing information.

2. Improve the host to record the power supply current and the secondary eddy current field in the receiving coil when it emits bipolar rectangular pulses, and use the layered component signal obtained as the main signal, which is convenient for later data processing and target analysis. Carrying out three-component calculation and interpretation avoids the limitations of single-component interpretation and is beneficial to distinguish different geological anomalies.

Description of drawings

The technical solutions of the present invention will be further specifically described below in conjunction with the accompanying drawings and specific embodiments.

Figure 1 is a schematic structural diagram of a foldable portable three-component transmitting and receiving wireframe.

Figure 2 is a schematic diagram of the structure of the folded vertical three-component transmitting and receiving wireframe.

Detailed ways

As shown in Figure 1, the transmitting and receiving cables are embedded in a special soft panel, and the center of the panel forms a hinge shaft in the horizontal direction, so that the panel can be folded for easy portability and operation. Among them, when the transmitting and receiving wire frames are arranged according to the center loop method, the distance between the transmitting wire frame and the receiving wire frame is 0.8-1.2m. The cable of the transmitting wire frame is 8-12 turns, and the side length is 1.8-2.2m, and the cable of the receiving wire frame is 18-22 turns, and the side length is 1.6-2.0m. A total of 3 sides are designed to be folded to form 3 panels. Usually, the panel can be unfolded, adjusted and its angle fixed to facilitate the sequential collection of transient electromagnetic data in the three directions of the top plate, bedding layer and bottom plate in front of the excavation working face, and realize one-point multi-component testing. . According to the section conditions of the roadway excavation working face on the spot, it is not necessary to adjust the included angle multiple times to measure the point and test, and the operation is more convenient.

Each wireframe panel includes a set of transmitting and receiving wireframes. The transmitting wireframes can be connected to the same transmitting connector as required, and the receiving wireframes can be connected to three independent receiving terminals. In this way, the transient electromagnetic field single-component transmission and reception of each single measurement point, as well as multi-component transmission and reception can be completed, that is, any set of transmission wireframes in the three-component transmission and reception system can be transmitted, and the reception wireframe can realize separate data Acquisition, or other multiple sets of receiving wireframes receive at the same time, to achieve the purpose of collecting multi-directional geological body induction field information. Among them, the transmitting system transmits bipolar rectangular pulses, and the transmitting frequencies include 2.5, 6.25, 12.5, 25, 62.5Hz and other frequencies; Eddy current field value.

The panel can be rotated appropriately to form three mutually perpendicular components for data collection, as shown in Figure 2.

The detection method based on the above-mentioned transient electromagnetic multi-component advanced detection device includes the following steps: after the on-site environment is sorted out, a wire frame is arranged at the excavation working face, and the multi-component acquisition wire frame is connected. Set the parameters required by the collection technology, and after testing the test system, perform single-point data collection according to the arrangement of measurement points and spacing. According to the state of the wireframe setting during data collection, it can realize one send and one receive, one send and three receive, and one send and one receive in sequence, which is suitable for different test requirements. The so-called sending and receiving means that among the three detection wireframes, the transmitting wireframe of one detection wireframe emits electromagnetic pulses, and the receiving wireframe receives transient electromagnetic data. The so-called one sending and three receiving means that among the three detection wire frames, the transmitting wire frame of one detection wire frame emits electromagnetic pulses, and the three receiving wire frames are started to receive transient electromagnetic data at the same time. The so-called sequential sending and receiving means that the three detection wireframes send and receive transient electromagnetic data in turn.

After completing the data collection of a measurement point, move the distance of the measurement point according to the interval of 0.2-0.5m, and then collect the data at the next point until the data collection of the entire test section is completed.

The data processing and interpretation methods of transient electromagnetic multi-component advanced detection are as follows. Combined with the empirical calculation formula of apparent resistivity in the late stage of the central loop line, after the test is completed, the data is sorted first, and the induced electromotive force data of the section at different points in the same direction are selected according to the test requirements to evaluate the data quality. The apparent resistivity calculation of a single measuring point is carried out, and the depth correction is carried out in combination with the geological conditions of the roadway excavation coal strata to obtain the corresponding depth-sounding resistivity profile. The late calculation formula is as follows:

${\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; sx</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; \&mu;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}{\sqrt{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; t</span>}}^{\frac{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}}}{<span\; class="notranslate">\; [</span>\frac{\mathrm{<span\; class="notranslate">\; n</span>}{\mathrm{<span\; class="notranslate">\; L</span>}}^{\mathrm{<span\; class="notranslate">\; 3</span>}}}{\mathrm{<span\; class="notranslate">\; \&pi;</span>}\sqrt{\mathrm{<span\; class="notranslate">\; \&pi;</span>}}}\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ]</span>}^{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; )</span>$

${\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; sz</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; \&mu;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}{\mathrm{<span\; class="notranslate">\; \&pi;t</span>}}{<span\; class="notranslate">\; [</span>\frac{\mathrm{<span\; class="notranslate">\; n</span>}{\mathrm{<span\; class="notranslate">\; L</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; 3</span>}}\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; z</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ]</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; b</span>}<span\; class="notranslate">\; )</span>$

In the formula: ρ _sx and ρ _sz represent the apparent resistivity calculated in the horizontal direction and vertical direction respectively; μ ₀ is the vacuum magnetic permeability; t is the observation time; n is the number of turns of the transmitting coil; I is the transmitting current; L is the transmitting rectangle Half the side length of the loop; H _x (t) and H _z (t) are the horizontal and vertical components of the transient magnetic field response, respectively.

According to the multi-point apparent resistivity calculation results of the test section, a comprehensive section of the rock and coal seam in front of the roadway is formed and expressed. Usually, the low-value abnormal area is determined according to the average resistivity value in the section, and the low-value abnormal area is determined by more than 3 times the average resistivity value. Combined with the detection target, it judges the abnormal area of low resistance value, interprets the abnormal position, and semi-quantitatively evaluates the water-rich degree and abnormal characteristics of coal rock formations according to the difference of abnormal value.

Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the present invention can be Modifications or equivalent replacements of the technical solutions without departing from the spirit and scope of the technical solutions of the present invention shall fall within the scope of the claims of the present invention.

Claims (8)

1. A transient electromagnetic multi-component advanced detection device is characterized in that it comprises three detection wire frames, each detection wire frame is arranged at a certain angle, and the detection wire frames arranged at different angles are used to collect instantaneous variable electromagnetic data. 2. The transient electromagnetic multi-component advanced detection device according to claim 1, characterized in that, the three detection wire frames have the same horizontal axis and are intersected at a certain angle, and the three detection wire frames respectively detect the excavation work Transient electromagnetic data in the three directions of the top plate, the bedding layer and the bottom plate in front of the front. 3. The transient electromagnetic multi-component advanced detection device according to claim 1, characterized in that, the three detection wire frames are orthogonal to each other in pairs, and the transient induction field data in three directions are respectively collected. 4. The transient electromagnetic multi-component leading detection device according to claim 2 or 3, characterized in that, the detection wire frame comprises a transmission wire frame and a reception wire frame, and the transmission wire frame and the reception wire frame return by the center When the lines are arranged separately, the distance between the transmitting line frame and the receiving line frame is 0.8-1.2m. 5. The transient electromagnetic multi-component advanced detection device according to claim 4, characterized in that, the cables of the transmitting wire frame are 8-12 turns and the side length is 1.8-2.2m, and the receiving wire frame is a cable 18-22 turns, side length 1.6-2.0m. 6 . The transient electromagnetic multi-component advanced detection device according to claim 5 , wherein the three detection wire frames are respectively embedded in soft panels. 7. A detection method based on the above-mentioned transient electromagnetic multi-component advanced detection device, is characterized in that, comprises the following steps: Adjust the three detection wireframes to the required angles and fix them, and place them at the first measurement point. Among the three detection wireframes, the transmission wireframe of one detection wireframe emits electromagnetic pulses, and its receiving wireframe receives transient electromagnetic data, or the three receiving wireframes are activated to receive transient electromagnetic data at the same time; or The three detection wireframes transmit and receive transient electromagnetic data in turn. 8. The detection method of the transient electromagnetic multi-component advanced detection device according to claim 7, is characterized in that, comprises the following steps: move the measuring point distance by 0.2-0.5m spacing after completing a measuring point data acquisition, and carry out the next point Data collection until the data collection of the entire test section is completed.

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