A time-space four-dimensional electrical detection system and method for physical model testing

Abstract

The present invention discloses a spatiotemporal four-dimensional electrical detection system and method for physical model tests, including an electrode sensor, an electrode multiplexer, a host computer and a power supply system. The electrode sensor includes a ring electrode and a supporting electrode rod, which can realize the multi-point and spatial three-dimensional arrangement of the electrode in the hole; the electrode multiplexer is used to connect a large number of ring electrodes to the host computer system for testing in sequence, so as to realize multi-point and large-scale uninterrupted detection; the host computer includes a computer and a control element, which can realize the functions of fast real-time measurement and digital display of results; the power supply system includes an indoor power supply, a high-voltage booster and a power supply circuit, which is used to provide long-term continuous and stable power supply to the host computer. The present invention solves the shortcomings of using traditional electrical methods that are not suitable for small geological bodies and the information revealed by electrical detection data gradually decreases as the measurement depth increases; and introduces time-shift technology into high-density electrical detection, thereby obtaining high-precision four-dimensional electrical data suitable for describing the spatiotemporal evolution of geological structures in model tests.

Description

Technical Field

[0001] The invention belongs to the field of geophysical electrical exploration, and in particular relates to a time-space four-dimensional electrical detection system and method for physical model experiments. Background Art

[0002] As the scale of major projects in my country gradually expands, the engineering geological problems revealed become increasingly complex, and major engineering disasters become increasingly prominent. Indoor model tests are widely used in scientific research in related fields due to their advantages such as small investment, short cycle, and accurate experimental data. General model test monitoring methods cannot fully reveal the spatiotemporal information of complex geological bodies. Geophysical methods can achieve complex geological structure detection. For example, high-density electrical method is a common geophysical exploration method. It is an array exploration method that concentrates electrical profiling and electrical depth sounding. It has the advantages of one-time wiring, fast automatic measurement, and high precision. In recent years, with the development of science and technology, the imaging technology of high-density electrical method has achieved a leapfrog development from one-dimensional to three-dimensional, which greatly improves the interpretation accuracy of geological information and can be used to detect complex geological structures and water content of geological bodies. However, due to the size limitations and accuracy requirements of indoor model tests, traditional geophysical methods such as high-density electrical method cannot be effectively applied to model test detection. Therefore, it is necessary to invent a time-space four-dimensional electrical detection system that can be used for large-scale physical model experiments, break through the shortcomings of traditional electrical detection ring electrodes and the limitation of the number of detection channels of electrical equipment, and realize high-precision and rapid detection of geological bodies with full coverage of spatial scale and long time scale. Summary of the invention

[0003] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a space-time four-dimensional electrical detection system and method for physical model experiments, so as to solve the shortcomings of traditional electrical detection ring electrodes and the limitation of the number of detection channels of electrical equipment, and realize high-precision and rapid detection of geological bodies with full coverage of spatial scale and long time scale.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0005] A spatiotemporal four-dimensional electrical detection system for physical model testing, comprising an electrode sensor, an electrode multiplexer and a host; the electrode sensor is connected to the electrode multiplexer, the electrode multiplexer is connected to the host, and the multiplexer can connect multiple electrode sensors to the host in sequence for testing;

[0006] The electrode sensor comprises an electrode support rod and a plurality of ring electrodes, wherein the electrode support rod is a hollow cylindrical structure, and a plurality of axially evenly distributed annular grooves are arranged on the outer wall of the electrode support rod; a transmission cable is arranged at the center of the electrode support rod, and the transmission cable extends from the top of the electrode support rod and is connected to a plurality of sensor plugs at the end thereof, and the sensor plugs correspond to the ring electrodes one by one; the ring electrodes are arranged in the annular grooves, and the ring electrodes are connected to the transmission cable at the center of the electrode support rod through an insulated wire from a small hole in the annular groove;

[0007] The electrode multiplexer comprises a sensor socket for plugging the sensor plug and a plurality of cable sockets; one end of the multi-core cable is plugged into the cable socket, and the other end of the multi-core cable is connected to the host;

[0008] The host includes a computer and a control element, and the control element includes an electrode switching control module, an AB power supply control module, an MN measurement control module and an ABMN control module; the electrode switching control module can control any four ring electrodes to be connected to the circuit as A, B, M, and N electrodes respectively, the AB power supply control module can supply power to the A and B electrodes and measure the current value flowing through, and the MN measurement control module can measure the voltage value at both ends of the M and N electrodes; when the A, B, M, and N electrodes are measured, the next group of four ring electrodes can be connected through the electrode switching control module, so as to complete the measurement in sequence and obtain a series of resistivity data.

[0009] The present invention also includes the following technical features:

[0010] Specifically, the detection system also includes a power supply system, which is connected to the host to provide the host with long-term continuous and stable power supply;

[0011] The power supply system includes an indoor power supply, a high-voltage booster and a power supply circuit; the high-voltage booster can be connected to the indoor power supply and connected to the host, and the high-voltage booster can realize AC to DC conversion and automatic voltage regulation.

[0012] Specifically, the electrode support rod has an outer diameter of 10 mm, an inner diameter of 3 mm, and a length of 1.5 m. Four annular grooves with a spacing of L are distributed on the electrode support rod, and the annular grooves are 1 mm deep and 3 mm wide.

[0013] The coil electrode is wound with 10 coils of wire, the wire is wound with 7 strands of copper wire and the wire cross section is 0.5mm 2 .

[0014] Specifically, a maximum of 30 electrode sensors can work simultaneously, and a total of 120 sensor plugs can be connected.

[0015] Specifically, the electrode multiplexer has 120 neatly arranged sensor sockets, which can connect up to 120 ring electrodes. Each 5×6 block, totaling 30 sensor sockets, are welded together inside the electrode multiplexer through wires to form a 30-core cable socket. The 120 sensor sockets eventually form four equidistantly arranged 30-core cable sockets in the electrode multiplexer.

[0016] Specifically, the computer is a single chip microcomputer capable of performing calculations, storage and display.

[0017] Specifically, the control element circuit: the preamplifier marked with IN increases the input impedance and receives the MN electrode signal; RC and U13 form a low-pass filter to filter out high-frequency interference signals and improve the signal-to-noise ratio; the operational amplifier marked with CR and the multi-way analog switch marked with X form a controllable gain amplifier to amplify weak signals and improve the measurement signal accuracy; the analog-to-digital converter marked with P (109) converts the analog quantity into a digital signal; the single-chip microcomputer marked with WR controls the operation of the circuit and saves data.

[0018] A time-space four-dimensional electrical detection method for physical model testing, the method is based on the detection system described in claim 1, and comprises the following steps:

[0019] Step 1, wiring: Place the electrode sensors vertically into the model box at equal intervals according to the model size. The number of electrode sensors is up to 30;

[0020] Step 2, model stacking: stack the soil into the model box layer by layer from bottom to top as required, and do not knock down the electrode sensors placed in the model box during the stacking process to ensure that the electrode sensors remain in place and are in close contact with the soil;

[0021] Step 3, equipment access: connect the sensor plugs connected to the top of all electrode sensors to the electrode multiplexer in sequence, connect the electrode multiplexer to the host with a multi-core cable to connect the electrode sensor to the host, connect the high-voltage booster to the indoor power supply, and connect the high-voltage booster to the host with a connecting wire;

[0022] Step 4, power on and program setting: turn on the host, set the number of connected sensors, and program the running mode and measurement cycle;

[0023] Step 5, equipment detection and measurement: First, check in the program whether all the coil electrodes are connected normally. If not, the model needs to be refilled; after all the coil electrodes are connected normally, click to start measuring; at this time, the control element connects the coil electrodes in groups of four in sequence according to the set running method until all measurements are completed and stop; after the set interval time, the second measurement cycle starts, and the previous measurement is repeated, and so on, until all measurement cycles are completed, thereby obtaining high-precision four-dimensional electrical data suitable for describing the spatiotemporal evolution of geological structures in model tests.

[0024] The electrode sensors are at most 30; when there are 30 electrode sensors, they are arranged in an array of three rows and ten columns;

[0025] Assume that the row numbers of the first to third rows are 0, 1 and 2 respectively; Assume that the column numbers of the first to tenth columns are 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9 respectively; The four ring electrodes on each electrode support rod are numbered 0, 1, 2 and 3 from top to bottom;

[0026] Then the running mode is:

[0027] The 10 electrodes in row 0 and layer 0 are powered for the first time, and 10 points are measured;

[0028] The 10 electrodes in the 1st layer of row 0 are powered for the second time, and 10 points are measured;

[0029] The 10 electrodes in the 2nd layer of row 0 are powered for the third time, and 10 points are measured;

[0030] The 10 electrodes in the 3rd layer of row 0 are energized for the 4th time, and 10 points are measured;

[0031] The 10 electrodes in the 0th layer of the 1st row are energized for the 5th time, and 10 points are measured;

[0032] The 10 electrodes in the 1st row and 1st layer were energized for the 6th time, and 10 points were measured;

[0033] The 10 electrodes in the 2nd layer of the 1st row were energized for the 7th time, and 10 points were measured;

[0034] The 10 electrodes in the 3rd layer of the 1st row were energized for the 8th time, and 10 points were measured;

[0035] The 10 electrodes in the 0th layer of the 2nd row are powered for the 9th time, and 10 points are measured;

[0036] The 10 electrodes in the 1st layer of the 2nd row are energized for the 10th time, and 10 points are measured;

[0037] The 10 electrodes in the 2nd row and the 2nd layer were energized for the 11th time, and 10 points were measured;

[0038] The 10 electrodes in the 3rd layer of the 2nd row were energized for the 12th time, and 10 points were measured;

[0039] After all electrodes have completed the measurement, electrical data of up to 120 points can be measured. At this time, one measurement cycle ends, and the second measurement cycle begins after the set interval time. The above steps are repeated, and so on, until all measurement cycles are completed, thereby obtaining high-precision four-dimensional electrical data suitable for describing the spatiotemporal evolution of geological structures in model tests.

[0040] Compared with the prior art, the present invention has the following technical effects:

[0041] ⑴ The present invention invents a ring electrode that is distributedly arranged on a supporting electrode rod, breaking through the limitations of traditional surface electrode arrangement and enabling multi-point and three-dimensional spatial arrangement of ring electrodes in a hole. Based on the new three-dimensional electrode arrangement, a new measurement principle is adopted to solve the problem that the accuracy and data of traditional electrical measurements decrease with increasing measurement depth, thereby enabling the model test to obtain rich high-precision electrical data.

[0042] ⑵ By inventing an electrode multiplexer, a large number of electrode sensors deployed in the model test are connected to the host system in turn for testing, breaking through the limitations on the number of electrodes connected to the traditional electrical method and the need for manual switching, thus achieving multi-point, large-scale, uninterrupted electrical detection and improving measurement efficiency.

[0043] ⑶ By optimizing the host system, which is composed of a computer system and control elements, the functions of fast real-time measurement and digital display of results can be realized, which can greatly improve the measurement efficiency of high-density electrical methods in model tests.

[0044] (4) By inventing a power supply system, which consists of an indoor power supply, a high-voltage booster and a power supply circuit, and has the functions of AC to DC conversion and automatic voltage adjustment, it can provide long-term, continuous and stable power supply to the host system, and realize long-depth, large-range and long-time detection.

[0045] ⑸ Innovatively introduce the time scale into the high-density electrical method, set the measurement cycle for continuous measurement, and thus obtain high-precision four-dimensional electrical data suitable for describing the spatiotemporal evolution of geological structures in model experiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is the overall framework diagram of the system of the present invention;

[0047] Figure 2 It is the structural diagram of the electrode sensor system and part of the transmission cable;

[0048] Figure 3 It is the structure diagram of the electrode multiplexer;

[0049] Figure 4 This is a schematic diagram of the host system;

[0050] Figure 5 Design circuit diagrams for host system control components;

[0051] Figure 6 This is a schematic diagram of the power supply system;

[0052] Figure 7 Design diagram for power supply circuit;

[0053] Figure 8 For the model and wiring examples;

[0054] Meaning of the figures:

[0055] 1. Electrode sensor, 2. Electrode multiplexer, 3. Host, 4. Power supply system;

[0056] 11. Electrode support rod, 12. Coil electrode, 13. Sensor plug;

[0057] 21. Sensor socket, 22. Cable socket;

[0058] 41. Indoor power supply, 42. High voltage booster, 43. Power supply circuit 43.

[0059] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0060] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0061] Embodiment 1:

[0062] like Figures 1 to 7 As shown, this embodiment provides a spatiotemporal four-dimensional electrical detection system for physical model experiments, including an electrode sensor 1, an electrode multiplexer 2 and a host 3; the electrode sensor 1 is connected to the electrode multiplexer 2, and the electrode multiplexer 2 is connected to the host 3. The multiplexer 2 can connect multiple electrode sensors 1 to the host 3 in sequence for testing, thereby realizing multi-point and large-scale uninterrupted electrical detection.

[0063] like Figure 2 As shown, the electrode sensor 1 includes an electrode support rod 11 and a plurality of ring electrodes 12. The electrode support rod 11 is a hollow cylindrical structure. A plurality of axially uniformly distributed annular grooves are provided on the outer wall of the electrode support rod 11. A transmission cable is provided at the center of the electrode support rod 11. The transmission cable extends from the top of the electrode support rod 11 and is connected to a plurality of sensor plugs 13 at its end. The sensor plugs 13 correspond to the ring electrodes 12 one by one. The ring electrodes 12 are arranged in the annular grooves. The cross-sectional area of ​​the ring electrodes 12 is 0.75mm. 2The insulated wire is connected from the small hole in the annular groove to the transmission cable in the center of the electrode support rod 11; the electrode can be arranged in multiple points and three-dimensional space in the hole; the supporting electrode rod 11 plays a supporting role, and the ring electrode 12 is equivalent to the electrode of the traditional high-density electrical method in order to connect the current to the model. It can be used as a measuring electrode and a power supply electrode respectively through the control of the host.

[0064] like Figure 3 As shown, the electrode multiplexer 2 includes a sensor socket 21 for plugging in the sensor plug 13 and a plurality of cable sockets 22; one end of the multi-core cable is inserted into the cable socket 22, and the other end of the multi-core cable is connected to the host 3; the function of the electrode multiplexer is to connect a large number of electrode sensors deployed in the model test with the host in turn for testing, so as to realize multi-point, large-scale and uninterrupted detection by the electrical method and improve the measurement efficiency.

[0065] like Figure 4 As shown, the host 3 includes a computer and a control element, and the control element includes an electrode switching control module, an AB power supply control module, an MN measurement control module and an ABMN control module; the electrode switching control module can control any four ring electrodes to access the circuit as A, B, M, and N electrodes respectively, the AB power supply control module can supply power to the A and B electrodes and measure the current value flowing through, and the MN measurement control module can measure the voltage value at both ends of the M and N electrodes; when the A, B, M, and N electrodes are measured, the next group of four ring electrodes 12 can be connected through the electrode switching control module, so as to complete the measurement in sequence to obtain a series of resistivity data.

[0066] like Figure 6 and Figure 7 As shown, the detection system also includes a power supply system 4, which is connected to the host 3 to provide the host 3 with long-term continuous and stable power supply; the power supply system 4 includes an indoor power supply 41, a high-voltage booster 42 and a power supply circuit 43; the high-voltage booster 42 can be connected to the indoor power supply 41, and the high-voltage booster 42 is connected to the host 3, and the high-voltage booster 42 can realize AC to DC conversion and automatic voltage regulation. Figure 7 This is the power supply circuit design diagram: When measuring power supply, M31 and M34 perform positive power supply; M33 and M32 perform negative power supply; HV1B amplifies R0 to read the current value; C1B is a backup amplifier.

[0067] The electrode support rod 11 has an outer diameter of 10 mm, an inner diameter of 3 mm, and a length of 1.5 m. Four annular grooves with a spacing of L are distributed on the electrode support rod 11, and the annular grooves are 1 mm deep and 3 mm wide.

[0068] The coil electrode 12 is wound with 10 coils of wire, the wire is wound with 7 strands of copper wire and the wire cross section is 0.5 mm 2 ;

[0069] The electrode support rod 11 is made of epoxy resin.

[0070] A maximum of 30 electrode sensors 1 can work simultaneously, and a total of 120 sensor plugs 13 can be connected.

[0071] There are 120 neatly arranged sensor sockets 21 on the electrode multiplexer 2, which can connect up to 120 ring electrodes 12. A total of 30 sensor sockets 21 in each 5×6 block are welded together by wires inside the electrode multiplexer 2 to form a 30-core cable socket 22. The 120 sensor sockets 21 eventually form four equidistantly arranged 30-core cable sockets 22 in the electrode multiplexer 2.

[0072] The computer is a single-chip microcomputer that can perform calculations, storage and display.

[0073] The control element realizes the above functions through a circuit diagram composed of multiple resistors, capacitors, amplifiers and corresponding chips. Figure 5 As shown, the control element circuit: the preamplifier marked with IN increases the input impedance and receives the MN electrode signal; RC and U13 form a low-pass filter to filter out high-frequency interference signals and improve the signal-to-noise ratio; the operational amplifier marked with CR and the multi-way analog switch marked with X form a controllable gain amplifier to amplify weak signals and improve the measurement signal accuracy; the analog-to-digital converter marked with P (109) converts analog quantities into digital signals; the single-chip microcomputer marked with WR controls the operation of the circuit and saves data.

[0074] Embodiment 2:

[0075] This embodiment provides a time-space four-dimensional electrical detection method for physical model testing. The method is based on a detection system and includes the following steps:

[0076] Step 1, wiring: Place the electrode sensors vertically into the model box at equal intervals according to the model size. The electrode sensors are required to be separated by a certain distance from the boundary to eliminate the influence of boundary effects. The number of electrode sensors is no more than 30;

[0077] Step 2, model filling: stack the soil into the model box layer by layer from bottom to top as required. Do not knock down the electrode sensor during the filling process to ensure that the electrode sensor remains in place and is in close contact with the soil. Figure 8 The sensor system and landfill example are shown in the figure;

[0078] Step 3, equipment access: connect the sensor plugs connected to the top of all electrode sensors to the electrode multiplexer in sequence, connect the electrode multiplexer to the host with a multi-core cable to connect the electrode sensor to the host, connect the high-voltage booster to the indoor power supply, and connect the high-voltage booster to the host with a connecting wire;

[0079] Step 4, power on and program setting: turn on the host, set the number of connected sensors, and program the running mode and measurement cycle;

[0080] Step 5, equipment detection and measurement: First, check in the program whether all the coil electrodes are connected normally. If not, the model needs to be refilled; after all the coil electrodes are connected normally, click to start measuring; at this time, the control element connects the coil electrodes in groups of four in sequence according to the set running method until all measurements are completed and stop; after the set interval time, the second measurement cycle starts, and the previous measurement is repeated, and so on, until all measurement cycles are completed, thereby obtaining high-precision four-dimensional electrical data suitable for describing the spatiotemporal evolution of geological structures in model tests.

[0081] The number of electrode sensors is at most 30; when the number of electrode sensors is 30, they are arranged in an array of three rows and ten columns;

[0082] like Figure 8 As shown, the row numbers of the first to third rows are 0, 1 and 2 respectively; the column numbers of the first to tenth columns are 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9 respectively; the four ring electrodes on each electrode support rod are numbered 0, 1, 2 and 3 from top to bottom;

[0083] The present invention is applicable to the model box running pole method, which can form resistivity data with extremely high measurement accuracy: the running pole method is:

[0084] The 10 electrodes in row 0 and layer 0 are powered for the first time, and 10 points are measured;

[0085] The 10 electrodes in the 1st layer of row 0 are powered for the second time, and 10 points are measured;

[0086] The 10 electrodes in the 2nd layer of row 0 are energized for the third time and 10 points are measured;

[0087] The 10 electrodes in the 3rd layer of row 0 are energized for the 4th time, and 10 points are measured;

[0088] The 10 electrodes in the 0th layer of the 1st row are energized for the 5th time, and 10 points are measured;

[0089] The 10 electrodes in the 1st row and 1st layer were energized for the 6th time, and 10 points were measured;

[0090] The 10 electrodes in the 2nd layer of the 1st row were energized for the 7th time, and 10 points were measured;

[0091] The 10 electrodes in the 3rd layer of the 1st row were energized for the 8th time, and 10 points were measured;

[0092] The 10 electrodes in the 0th layer of the 2nd row are powered for the 9th time, and 10 points are measured;

[0093] The 10 electrodes in the 1st layer of the 2nd row are energized for the 10th time, and 10 points are measured;

[0094] The 10 electrodes in the 2nd row and the 2nd layer were energized for the 11th time, and 10 points were measured;

[0095] The 10 electrodes in the 3rd layer of the 2nd row were energized for the 12th time, and 10 points were measured;

[0096] After all electrodes have completed the measurement, electrical data of up to 120 points can be measured. At this time, one measurement cycle ends, and the second measurement cycle begins after the set interval time. The above steps are repeated, and so on, until all measurement cycles are completed, thereby obtaining high-precision four-dimensional electrical data suitable for describing the spatiotemporal evolution of geological structures in model tests.

[0097] More specifically, electrodes are represented by rows, columns and electrode numbers. For example, the electrode number of the first electrode (the electrode number of electrode No. 1 is 0) in the first column (column number 0) of the middle row (row number 1) is (1,0,0); and the electrode number of the fourth electrode (the electrode number of electrode No. 4 is 3) in the tenth column (column number 9) of the outermost row (row number 2) is (2,9,3).

[0098] The following table lists the row number, column number, coordinate number and electrode number of the power supply measurement electrode. The order of the power supply measurement of 120 electrodes in 12 times is shown in the following table.

[0099] Table 1 Power supply measurement Table 1

[0100]

[0101]

[0102] Table 2 Power supply measurement Table 2

[0103]

[0104] Table 3 Power supply measurement Table 3

[0105]

[0106]

[0107] Table 4 Power supply measurement Table 4

[0108]

[0109] Table 5 Power supply measurement Table 5

[0110]

[0111] Table 6 Power supply measurement Table 6

[0112]

[0113]

[0114] At this point, a measurement cycle is completed, forming a set of three-dimensional electrical data. The model box uses an automatic water injection device to simulate the changes in groundwater. After the set interval time, the second measurement cycle begins, and so on, until the end of the model test, thereby obtaining high-precision four-dimensional electrical data suitable for describing the spatiotemporal evolution of geological structures in model tests.

Claims

1. A time-space four-dimensional electrical detection system for physical model testing, characterized in that: The device comprises an electrode sensor (1), an electrode multiplexer (2) and a host (3); the electrode sensor (1) is connected to the electrode multiplexer (2), the electrode multiplexer (2) is connected to the host (3), and the multiplexer (2) can connect a plurality of electrode sensors (1) to the host (3) in sequence for testing; The electrode sensor (1) comprises an electrode support rod (11) and a plurality of ring electrodes (12); the electrode support rod (11) is a hollow cylindrical structure, and a plurality of axially evenly distributed annular grooves are provided on the outer wall of the electrode support rod (11); a transmission cable is provided at the center of the electrode support rod (11), the transmission cable extends from the top of the electrode support rod (11) and is connected to a plurality of sensor plugs (13) at the end thereof, and the sensor plugs (13) correspond to the ring electrodes (12) one by one; the ring electrodes (12) are arranged in the annular groove, and the ring electrodes (12) are connected to the transmission cable at the center of the electrode support rod (11) through an insulated wire from a small hole in the annular groove; The electrode multiplexer (2) comprises a sensor socket (21) for plugging the sensor plug (13) and a plurality of cable sockets (22); one end of the multi-core cable is plugged into the cable socket (22), and the other end of the multi-core cable is connected to the host (3); The host (3) comprises a computer and a control element, wherein the control element comprises an electrode switching control module, an AB power supply control module, an MN measurement control module and an ABMN control module; the electrode switching control module can control any four coil electrodes to be connected to the circuit as A, B, M and N electrodes respectively, the AB power supply control module can supply power to the A and B electrodes and measure the current value flowing therethrough, and the MN measurement control module can measure the voltage value at both ends of the M and N electrodes; when the A, B, M and N electrodes are measured, the next group of four coil electrodes (12) can be connected through the electrode switching control module, thereby completing the measurement in sequence to obtain a series of resistivity data; The detection system also includes a power supply system (4), which is connected to the host (3) to provide the host (3) with long-term continuous and stable power supply; The power supply system (4) comprises an indoor power supply (41), a high-voltage booster (42) and a power supply circuit (43); the high-voltage booster (42) can be connected to the indoor power supply (41), and the high-voltage booster (42) is connected to the host (3); the high-voltage booster (42) can realize AC-to-DC conversion and automatic voltage regulation; The electrode support rod (11) has an outer diameter of 10 mm, an inner diameter of 3 mm, and a length of 1.5 m. Four annular grooves with a spacing of L are distributed on the electrode support rod (11), and the annular grooves are 1 mm deep and 3 mm wide. The coil electrode (12) is formed by winding 10 coils of wire, the wire is wound by 7 strands of copper wire and the wire cross section is 0.5 mm 2 .

2. The time-space four-dimensional electrical detection system for physical model testing according to claim 1, characterized in that: A maximum of 30 electrode sensors (1) can work simultaneously, and a total of 120 sensor plugs (13) can be connected.

3. The time-space four-dimensional electrical detection system for physical model testing according to claim 2, characterized in that: The electrode multiplexer (2) has 120 neatly arranged sensor sockets (21) which can be connected to a maximum of 120 ring electrodes (12). Each block of 5×6 sensor sockets (21) totaling 30 are welded together inside the electrode multiplexer (2) through wires to form a 30-core cable socket (22). The 120 sensor sockets (21) eventually form four equidistantly arranged 30-core cable sockets (22) on the electrode multiplexer (2).

4. The time-space four-dimensional electrical detection system for physical model testing according to claim 1, characterized in that: The computer is a single chip microcomputer capable of performing calculations, storage and display.

5. The time-space four-dimensional electrical detection system for physical model testing according to claim 1, characterized in that: The control element circuit: the preamplifier marked with IN increases the input impedance and receives the MN electrode signal; RC and U13 form a low-pass filter to filter out high-frequency interference signals and improve the signal-to-noise ratio; the operational amplifier marked with CR and the multi-channel analog switch marked with X form a controllable gain amplifier to amplify weak signals and improve the measurement signal accuracy; the analog-to-digital converter marked with P (109) converts analog quantities into digital signals; the single-chip microcomputer marked with WR controls the operation of the circuit and saves data.

6. A time-space four-dimensional electrical detection method for physical model testing, characterized in that: The method is based on the detection system according to claim 1, comprising the following steps: Step 1, wiring: Place the electrode sensors vertically into the model box at equal intervals according to the model size. The number of electrode sensors is up to 30; Step 2, model stacking: stack the soil into the model box layer by layer from bottom to top as required, and do not knock down the electrode sensors placed in the model box during the stacking process to ensure that the electrode sensors remain in place and are in close contact with the soil; Step 3, equipment access: connect the sensor plugs connected to the top of all electrode sensors to the electrode multiplexer in sequence, connect the electrode multiplexer to the host with a multi-core cable to connect the electrode sensor to the host, connect the high-voltage booster to the indoor power supply, and connect the high-voltage booster to the host with a connecting wire; Step 4, power on and program setting: turn on the host, set the number of connected sensors, and program the running mode and measurement cycle; Step 5, equipment detection and measurement: First, check in the program whether all the coil electrodes are connected normally. If not, the model needs to be refilled; after all the coil electrodes are connected normally, click to start measuring; at this time, the control element connects the coil electrodes in groups of four in sequence according to the set running method until all measurements are completed and stop; after the set interval time, the second measurement cycle starts, and the previous measurement is repeated, and so on, until all measurement cycles are completed, thereby obtaining high-precision four-dimensional electrical data suitable for describing the spatiotemporal evolution of geological structures in model tests.

7. The time-space four-dimensional electrical detection method for physical model testing according to claim 6, characterized in that: The electrode sensors are at most 30; when there are 30 electrode sensors, they are arranged in an array of three rows and ten columns; Assume that the row numbers of the first to third rows are 0, 1 and 2 respectively; Assume that the column numbers of the first to tenth columns are 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9 respectively; The four ring electrodes on each electrode support rod are numbered 0, 1, 2 and 3 from top to bottom; Then the running mode is: The 10 electrodes in row 0 and layer 0 are powered for the first time, and 10 points are measured; The 10 electrodes in the 1st layer of row 0 are powered for the second time, and 10 points are measured; The 10 electrodes in the 2nd layer of row 0 are energized for the third time and 10 points are measured; The 10 electrodes in the 3rd layer of row 0 are energized for the 4th time, and 10 points are measured; The 10 electrodes in the 0th layer of the 1st row are energized for the 5th time, and 10 points are measured; The 10 electrodes in the 1st row and 1st layer were energized for the 6th time, and 10 points were measured; The 10 electrodes in the 2nd layer of the 1st row were energized for the 7th time, and 10 points were measured; The 10 electrodes in the 3rd layer of the 1st row were energized for the 8th time, and 10 points were measured; The 10 electrodes in the 0th layer of the 2nd row are powered for the 9th time, and 10 points are measured; The 10 electrodes in the 1st layer of the 2nd row are energized for the 10th time, and 10 points are measured; The 10 electrodes in the 2nd row and the 2nd layer were energized for the 11th time, and 10 points were measured; The 10 electrodes in the 3rd layer of the 2nd row were energized for the 12th time, and 10 points were measured; After all electrodes have completed the measurement, electrical data of up to 120 points can be measured. At this time, one measurement cycle ends, and the second measurement cycle begins after the set interval time. The above steps are repeated, and so on, until all measurement cycles are completed, thereby obtaining high-precision four-dimensional electrical data suitable for describing the spatiotemporal evolution of geological structures in model tests.

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