A leakage diagnosis device for earth-rock dam based on transient electromagnetic method and its use method

Abstract

The invention discloses a leakage diagnosis device for earth-rock dam based on transient electromagnetic method and a method for using the device. The device comprises a coil support composed of sides a, b, c and d. The structures of sides b and d of the coil support are symmetrically arranged. Side b has a hollow structure and a support rod and a guide rod are arranged in sequence from the outside to the inside of the hollow structure. One end of the support rod is rotatably installed in the hollow structure of side b through a fixed rod. The support rod can rotate around the fixed rod and can move back and forth on the fixed rod. The fixed rod can move back and forth along the length direction of the hollow structure of side b. The guide rod is arranged above the support rod and one end of the guide rod is rotatably installed on side b through a rotating mechanism. Side c has a hollow structure and a rotating rod is rotatably installed therein. Side a is provided with a towing mechanism for towing the coil support to move. A transmitting coil and a receiving coil are arranged on the inner side of the coil support. The transmitting coil, the receiving coil, the guide rod and the rotating rod are fixed on a plane through a fixing member.

Description

Technical Field

[0001] The invention relates to the technical field of detecting hidden dangers of earth-rock dams, and in particular to an earth-rock dam leakage diagnosis device based on transient electromagnetic method and a use method thereof. Background Art

[0002] Dams are the most common water-retaining structures in water storage facilities such as reservoirs, rivers, ditches, and polder areas. With the continuous advancement of the work of filling the gaps in water conservancy projects, the management of dam leakage hazards has become the key to restricting the standardization of reservoir dams. In order to ensure the safe operation of reservoirs, water conservancy projects are subject to various forms of daily, pre-flood, annual and special inspections, mainly including visual methods such as looking, listening, touching, smelling, and stepping, or simple tools and equipment such as hammers, chisels, steel tape measures, magnifying glasses, and litmus papers to inspect the surface and abnormal phenomena of the project. However, the leakage hazards of reservoir dams are hidden in space and variable in time. Conventional observation methods can only detect sections such as leakage damage that have occurred, but are powerless against damage that is occurring or is about to occur inside the dam.

[0003] At present, the search for leakage hazards of reservoir dams is mainly divided into two types of methods: destructive and non-destructive. The destructive method mainly uses manual drilling to drill into the dam for sampling. By analyzing the properties of the sample rock and soil and the injection and pressure test in the borehole, it is inferred whether there is a weak leakage area. This method can directly reveal the structure and characteristics of the rock and soil, but the arrangement of the boreholes has a certain randomness, and whether the hidden danger area can be locked is somewhat accidental, and it also causes certain damage to the dam itself; the resistivity method is the most important geophysical detection method in the detection of leakage hazards. Since the weak leakage area has an obvious low resistance effect compared with the surrounding medium, the resistivity test method can intuitively and efficiently reveal the spatial location information of the hidden danger body such as the burial depth, scale, and shape. However, with the continuous aggravation of the surface hardening phenomenon of reservoir dams (concrete, block stone, prefabricated block and other dam surfaces), the layout of power supply and measurement electrodes in the resistivity method has become a difficult problem in engineering. It should be pointed out that during the construction of the dam, due to the limitations of historical conditions, technical means and economic levels, the contact area between the dam body fill and the mountain rock foundation is a high-risk area for leakage. Due to the steep mountains on both sides, the space for arranging the survey lines is limited. Testing methods such as high-density electrical methods have certain blind spots in this area. In addition, due to the high-resistance shielding effect of the mountain rock mass, common conductive electrical methods are difficult to identify the existence of this hidden danger.

[0004] Transient electromagnetic method (TEM) is an induction-type time domain electromagnetic method. It transmits a field pulse signal to the ground through an ungrounded loop or grounded electrode. During the interval of a periodic signal, the ground receiving coil is used to collect the secondary field from the underground at different times. The distribution of the geological medium is inferred by analyzing the induced electromotive force signals at different times. This technology has the advantages of no need to install electrodes, high detection efficiency, and sensitivity to low resistance. It is widely used in mine water hazard detection, tunnel advance prediction, metal mineral exploration and other fields. However, reservoir dams have a unique structure and limited space. Large-sized coils are difficult to be used in reservoir dam hidden danger detection. In addition, dam leakage includes dam body, dam foundation, and around-dam leakage. It is necessary to consider the adjustment of the coil normal direction with the direction of the leakage point. How to implement a suitable detection system for the location of hidden dangers becomes the key to the problem.

[0005] At present, transient electromagnetic detection in earth-rock dams mainly adopts large coils, which have large shallow blind areas, are inconsistent with the actual size of the dam, are inconvenient to use, and have difficulty in flexibly detecting different directions of the dam shoulder. Summary of the invention

[0006] The purpose of the present invention is to solve the problem of limited space on the reservoir dam site and the use of hardened protection treatment on the dam top and dam slope. Taking into account factors such as the location, burial depth, and variable spatial positioning information of the leakage channel, a transient electromagnetic-based earth-rock dam leakage diagnosis device and a method of use are proposed.

[0007] A leakage diagnosis device for earth-rock dam based on transient electromagnetic method, comprising a coil support composed of sides a, b, c and d, the structures of sides b and d of the coil support are arranged symmetrically, the side b of the coil support has a hollow structure, and a support rod and a guide rod are arranged in sequence from the outside to the inside of the hollow structure, one end of the support rod is rotatably installed in the hollow structure of the side b of the coil support through a fixed rod, the support rod can rotate around the fixed rod and can move back and forth on the fixed rod, and the fixed rod can move back and forth along the length direction of the hollow structure of the side b of the coil support; the guide rod is arranged above the support rod and one end of the guide rod is rotatably installed on the side b of the coil support through a rotating mechanism; the side c of the coil support also has a hollow structure and a rotating rod is rotatably installed therein; the side a of the coil support is provided with a towing mechanism for towing the coil support to move; a transmitting coil and a receiving coil are arranged on the inner side of the coil support; the transmitting coil, the receiving coil, the guide rod and the rotating rod are fixed on a plane through a fixing member. Preferably, the guide rod is provided with a plurality of marks, and the support rod supports the corresponding mark positions, so that the angle between the guide rod and the ground can be adjusted.

[0008] Preferably, the fixing rod is arranged away from the rotating mechanism; the end of the supporting rod has a semicircular ring, and the fixing rod passes through the semicircular ring.

[0009] Preferably, the rotating mechanism includes a small pulley and a bearing; a small pulley is connected to the lower part of one end of the guide rod, the small pulley is fixed on the bearing, and the bearing is installed on the coil bracket, and the guide rod can rotate in the direction of 0-90° through the small pulley.

[0010] Preferably, a level is installed on the surface of side a of the coil support, and a layer of wear-resistant plastic is fixed around the lower surface of the coil support.

[0011] Preferably, a cushion block is installed in the hollow structure of the coil support b and below the guide rod, and is used to support the guide rod to be placed horizontally.

[0012] Preferably, the towing mechanism includes a towing rope, and the two ends of the towing rope are fixed to the edge of the coil bracket a through a towing ring. Preferably, the earth-rock dam leakage diagnosis device also includes a transient electromagnetic host, the transmitting coil is connected to the transient electromagnetic host through a transmitting cable, and the receiving coil is connected to the transient electromagnetic host through a receiving cable; the electromagnetic host is connected to the data control platform through a wireless transmitter.

[0013] In a second aspect, the present invention also provides a method for using the earth-rock dam leakage diagnosis device.

[0014] The steps include:

[0015] Step 1: Leakage Survey

[0016] (1) Visit the three responsible persons of the reservoir dam and the surrounding villagers to learn about the engineering data during the reservoir construction period, including the source of the dam filling materials, the dam type, whether the dam foundation is in the bedrock, and whether there are any abnormal phenomena during the construction process;

[0017] (2) Collect historical data on reservoir reinforcement over the years, including safety appraisal, engineering geological survey, risk elimination and reinforcement design, and construction data;

[0018] (3) Conduct a site survey of the reservoir to investigate the spatial location of the leakage point, the turbidity of the water body, the apparent characteristics of the dam, and the relationship between the leakage amount and the reservoir water level;

[0019] (4) Integrate the above survey data into a reservoir dam database;

[0020] Step 2: Hazard detection

[0021] (1) When the leakage characteristics are manifested as leakage of the dam body and dam foundation, the earth-rock dam leakage diagnosis device is arranged on the anti-seepage section of the dam top; during detection, the dam top is marked from left to right at intervals of 1m, with a distance of 0.5m from the left dam head as the starting point; the center point of the coil bracket is coincident with the starting point of the survey line to ensure that the coil is in a horizontal state, the transmitting coil is connected to the transient electromagnetic host through a transmitting cable, the receiving coil is connected to the transient electromagnetic host through a receiving cable, and the transient electromagnetic host is connected to the data control platform through a wireless transmitter agreed on the network. The number of turns of the transmitting and receiving coils, the transmitting frequency, the transmitting current, the number of superpositions, and the measurement mode parameters are adjusted on the data control platform. After the parameter settings are received, the data control platform sends a collection command to the transient electromagnetic host and recovers the secondary field signal collected in the transient electromagnetic host; after the collection of a single measuring point is completed, the position of the device is moved in sequence according to the interval of 1m, and each measuring point on the survey line completes the data collection and recovery, so that the induced electromotive force signal of the dam at different positions on a single section can be obtained;

[0022] (2) When the leakage characteristics show leakage around the dam, the earth-rock dam leakage diagnosis device is arranged on the dam head closest to the leakage point; during detection, the coil bracket is horizontally placed at the dam head position to ensure that the level gauge on the coil bracket is in a horizontal state, the transmitting coil is connected to the transient electromagnetic host through the transmitting cable, the receiving coil is connected to the transient electromagnetic host through the receiving cable, and the transient electromagnetic host is connected to the data control platform through the wireless sensor agreed on by the network. The number of turns of the transceiver coil, the transmitting frequency, the transmitting current, the number of superpositions, and the measurement mode parameters are adjusted on the data control platform. After the parameter settings are received, the data control platform sends a signal to the transient electromagnetic host. Send the acquisition command and recycle the secondary field signal collected in the transient electromagnetic host. When the coil horizontal signal is collected, the support rod is used to support the marked position of the guide rod, and the angle between the guide rod and the horizontal plane can be adjusted to 15°, so as to control the plane normal of the guide rod to point to the dam shoulder. The data control platform sends the acquisition command to the transient electromagnetic host and recycles the secondary field signal collected in the transient electromagnetic host. The angle between the guide rod and the ground can be adjusted to 30°, 45°, 60°, and 90° in turn. The data collection and recovery are completed at each measuring point on the survey line, and the induced electromotive force signals of different directions of the dam shoulder on a single section can be obtained.

[0023] (3) After the dam top detection in step 1) and step 2) is completed, when the leakage characteristics are manifested as leakage of the dam body and dam foundation, the earth-rock dam leakage diagnosis device can arrange detection lines at different elevations along the longitudinal direction of the dam on the back slope. When detecting the measuring points on each measuring line, the coil should be kept horizontal, and finally the induced electromotive force signals at different elevations and different positions are obtained; when the leakage characteristics are manifested as leakage around the dam, the measuring lines can be arranged at different elevations along the transverse direction of the dam. During each detection, the transmitting coil and the receiving coil are rotated in five directions, and the coil support should be kept horizontal when the coil angle is changed;

[0024] (4) The number of longitudinal survey lines of the dam is greater than 3, the number of measuring points of the transverse survey line of the dam is greater than 3, and each measuring point measures at least 3 angles;

[0025] Step 3: Leakage Identification

[0026] (1) When the leakage characteristics are manifested as leakage of the dam body and dam foundation, the water conservancy transient electromagnetic supporting software is used to jointly process the data of each measuring point on each survey line. The processing process includes importing data, modifying channel parameters, correcting interference, and mapping apparent resistivity, so as to obtain the measuring point-voltage curve and apparent resistivity profile of each survey line;

[0027] According to the changing characteristics of the measuring point-voltage curve, determine the leakage anomaly in the horizontal direction;

[0028] According to the change characteristics of the apparent resistivity profile, the leakage anomaly in the vertical direction is determined, and the spatial location information such as the scope, burial depth, and strike direction of the comprehensive low-resistance anomaly area is delineated;

[0029] Conduct joint 3D imaging of apparent resistivity profiles on multiple survey lines to effectively eliminate false anomalies on a single survey line. Combined with leakage survey data, the spatial distribution area of ​​the leakage channel can be outlined to provide target areas for further treatment of reservoir dam hidden dangers.

[0030] (2) When the leakage characteristics show leakage at the dam shoulder, the water conservancy transient electromagnetic supporting software is used to jointly process the data of each angle point at each measuring point. The processing flow includes importing data, modifying channel parameters, correcting interference, and mapping apparent resistivity, so as to obtain the angle-voltage curve and apparent resistivity profile of each measuring point;

[0031] According to the changing characteristics of the angle-voltage curve, determine the leakage anomaly at each measuring angle;

[0032] According to the change characteristics of the apparent resistivity profile, the leakage anomaly along the angle direction is determined, and the scope, burial depth, and spatial location information of the low-resistance anomaly area are delineated;

[0033] The apparent resistivity profiles at multiple angle points are jointly imaged in three dimensions to effectively eliminate false anomalies at a single angle point. Combined with the reservoir dam database, the spatial distribution area of ​​the leakage channel is outlined, providing a target area for further treatment of hidden dangers of the reservoir dam.

[0034] The technical solution of the present invention is further described below:

[0035] The invention improves the direction and type of transient electromagnetic coils according to the location of hidden dangers in reservoirs and dams, and provides on-site testing and interpretation methods. It is mainly used for the detection of hidden dangers in reservoirs, dams, dikes, mountain ponds, seawalls and urban roads.

[0036] The earth-rock dam hidden danger detection device based on transient electromagnetic provided by the present invention has the characteristics of easy installation, convenient carrying, flexible testing, etc., realizes the emission and reception of electromagnetic fields in occasions such as the dam top and dam slope, and can adjust the detection direction of the coil according to the change of the leakage point position of the dam shoulder joint. When detecting the hidden danger of leakage of the reservoir dam, the transmitting wire, the receiving antenna and the transient electromagnetic host are connected by a cable, and the parameters such as the number of turns of the transceiver coil, the transmission frequency, the transmission current, the number of superpositions, and the measurement mode are adjusted to collect the induced electromotive force signals at different depths inside the dam. After the collection of a single measuring point is completed, the position of the device is moved in sequence according to the agreed spacing, and the induced electromotive force signals at different positions of the dam on a single section can be obtained. When all points on the measuring line are collected, the secondary field data body recovered by the data processing platform according to a certain network protocol is processed to obtain a time-induced electromotive force curve and an apparent resistivity profile. Finally, combined with the geological data of the dam and the operation monitoring data, the cause of the dam leakage and the distribution characteristics of the leakage weak zone are inferred, providing a targeted target area for the leakage treatment of the earth-rock dam.

[0037] A leakage diagnosis device for earth-rock dam based on transient electromagnetic method comprises a towing rope 2, a coil support 4, a coil, a cable, a transient electromagnetic host, a data control platform and the like.

[0038] The towing rope 2 is a nylon braided rope with good wear resistance, and its head and tail ends are fixed on the coil support traction ring 3 and the traction ring 3 is symmetrically distributed with the center of the coil. A high-pressure resistant hard glass fiber hollow circular tube 1 (outer 25mm*inner 19mm*length 0.2m) is sleeved on the towing rope 2; during on-site detection, after adjusting the hollow circular tube 1 to the appropriate position of the towing rope, the coil support 4 can be moved on the dam surface by holding the hollow circular tube;

[0039] The coil support 4 is a square plastic frame (including sides a, b, c, and d), each side of the coil support is 58 cm long, 3.5 cm wide, and 3.5 cm high. There is a 0.5 cm thick wear-resistant plastic at the bottom between the coils to increase the life of the coil support during long-term use on the ground;

[0040] The side a of the coil support 4 mainly controls the direction and speed of coil traction, and there is a traction ring 3 on the side a of the coil support;

[0041] The structures of the b side and the d side of the coil support 4 are the same and are symmetrically arranged. For the sake of simplicity, only the structure of the d side of the coil support is described: the d side of the coil support 4 has a hollow structure inside, and the hollow structure of the d side of the coil support 4 is provided with a support rod 5 and a guide rod 6 from the outside to the inside in sequence. The support rod 5 is a rectangular parallelepiped, 20.5 cm long, 1 cm wide, and 1 cm high. One end of the support rod 5 is a semicircular ring 7 with a radius of 0.5 cm. The center of the semicircular ring passes through a fixed rod 8, and the fixed rod 8 is 3.5 cm long. The support rod 5 can move laterally on the fixed rod 8; the fixed rod 8 passes through the semicircular ring 7 and both ends of the fixed rod are installed in the hollow structure of the d side of the coil support and can move along its length direction; a guide rod 6 is also provided on the inside of the hollow structure of the d side of the coil support, and the guide rod 6 is located above the support rod 5, such as Figure 3 The guide rod 6 is a rectangular parallelepiped with a length of 50 cm, a width of 1 cm, and a height of 1 cm. A small pulley 11 is provided at the lower part of one end of the guide rod 6. The small pulley 11 is fixed on a bearing 10. The guide rod 6 can be rotated vertically in the range of 0 to 90 degrees through the small pulley 11. A cushion block 12 is placed at the lower middle part of the guide rod 6 to support the guide rod to keep it horizontal.

[0042] The coil comprises a transmitting coil and a receiving coil, and the transmitting coil and the receiving coil are bundled into one;

[0043] The coil support has a rotating rod on its c side, and the rotating rod is used to fix the transmitting coil and the receiving coil. Both ends of the rotating rod 13 are connected to the fixed shaft 14.

[0044] The guide rod 6 , the rotating rod 13 , the transmitting coil 15 and the receiving coil 16 on the coil support 4 are fixed on the same plane by a tie bar 23 .

[0045] The data control platform 21 controls the transient electromagnetic host 20 by wireless transmission. When data collection starts, the data control platform 21 sends a collection command to the transient electromagnetic host 20 according to a certain protocol. When data collection ends, the data control platform recovers the data file from the transient electromagnetic host. The data processing platform and the transient electromagnetic host transmit signals in real time to ensure that the collected transient electromagnetic data can be displayed in time, so as to evaluate the data quality.

[0046] The transient electromagnetic coil is fixed between the b, c, and d side coils, the transmitting coil 15 is connected to the transient electromagnetic host 20 through a transmitting cable, and the receiving coil 16 is connected to the transient electromagnetic host 20 through a receiving cable;

[0047] The surface of side a of the coil support 4 is provided with a level gauge 22, which can detect the level of the coil support during the measurement process;

[0048] The support rod 5 is lower in height than the guide rod 6, and the support rod 5 can be moved on the fixed rod to the bottom of the guide rod 6;

[0049] The fixing rod is fixed to the middle of the side b and the side d of the coil support, and the guide rod is kept horizontal by the pulley and the support block when placed horizontally; the bearing is fixed to one end of the side b and the side d close to the side c;

[0050] There are marks on the guide rod, and the corresponding mark position is supported by the support rod to adjust the angle between the guide rod and the ground, so as to control the plane normal of the guide rod. The angle between the guide rod and the ground can be 15°, 30°, 45°, 60°, and 90°. In particular, during on-site detection, the angle between the guide rod and the ground should be increased step by step from small to large.

[0051] In particular, when detecting the dam crest and the backslope bridleway, the transient electromagnetic coil bracket is kept horizontal and the normal direction is vertically downward;

[0052] The data processing platform can perform functions such as denoising, normalization, apparent resistivity calculation and display on transient electromagnetic data.

[0053] A method for using a transient electromagnetic-based earth-rock dam leakage diagnosis device includes leakage investigation, hidden danger detection and leakage identification.

[0054] 1. Leakage investigation

[0055] (4) Visit the three responsible persons of the reservoir dam and the surrounding villagers to learn about the engineering data during the construction of the reservoir, including the source of the dam filling materials, the dam type, whether the dam foundation is in bedrock, and whether there are any abnormal phenomena during the construction process;

[0056] (5) Collect historical data on reservoir reinforcement over the years, including safety appraisal, engineering geological survey, risk elimination and reinforcement design, and construction data;

[0057] (6) Conduct a site survey of the reservoir to investigate the spatial location of the leakage point, the turbidity of the water body, the apparent characteristics of the dam, and the relationship between the leakage amount and the reservoir water level;

[0058] (4) Integrate the above survey data into the reservoir dam database.

[0059] 2. Hidden danger detection

[0060] (5) When the leakage characteristics are manifested as leakage of the dam body and dam foundation, the earth-rock dam leakage diagnostic device is arranged on the anti-seepage section of the dam top. During detection, the dam top is marked from left to right at intervals of 1m, with a distance of 0.5m from the left dam head as the starting point; the center point of the transient electromagnetic coil bracket coincides with the starting point of the survey line to ensure that the coil is in a horizontal state, the transmitting coil is connected to the transient electromagnetic host through a transmitting cable, the receiving coil is connected to the transient electromagnetic host through a receiving cable, and the transient electromagnetic host is connected to the data control platform through a wireless transmitter agreed on the network. The number of turns of the transceiver coil, the transmitting frequency, the transmitting current, the number of superpositions, the measurement mode and other parameters are adjusted on the data control platform. After the parameter settings are received, the data control platform sends a collection command to the transient electromagnetic host and recovers the secondary field signal collected in the transient electromagnetic host; after the collection of a single measuring point is completed, the position of the device is moved in sequence at intervals of 1m, and each measuring point on the survey line completes the collection and recovery of data, so that the induced electromotive force signals of different positions of the dam on a single section can be obtained;

[0061] (6) When the leakage characteristics show leakage around the dam, the earth-rock dam leakage diagnosis device is arranged on the dam head closest to the leakage point. During detection, the transient electromagnetic coil bracket is placed horizontally at the dam head to ensure that the level gauge on the coil bracket is in a horizontal state. The transmitting coil is connected to the transient electromagnetic host through the transmitting cable, and the receiving coil is connected to the transient electromagnetic host through the receiving cable. The transient electromagnetic host is connected to the data control platform through the wireless sensor agreed on by the network. The number of turns of the transceiver coil, the transmitting frequency, the transmitting current, the number of superpositions, the measurement mode and other parameters are adjusted on the data control platform. After the parameter settings are received, the data control platform sends a collection command to the transient electromagnetic host and collects the data in the transient electromagnetic host. The secondary field signal is recovered; when the horizontal signal of the coil is collected, the support rod is used to support the marked position of the guide rod, and the angle between the guide rod and the horizontal plane can be adjusted to 15°, so as to control the plane normal of the guide rod to point to the dam shoulder. The data control platform sends a collection command to the transient electromagnetic host, and recovers the secondary field signal collected in the transient electromagnetic host. The angle between the guide rod and the ground can be adjusted to 30°, 45°, 60°, and 90° in turn. The data collection and recovery are completed at each measuring point on the survey line, and the induced electromotive force signals at different positions of the dam shoulder on a single section can be obtained.

[0062] (7) After the dam top detection in step 1) and step 2) is completed, when the leakage characteristics are manifested as leakage of the dam body and dam foundation, the earth-rock dam leakage diagnosis device can arrange detection lines at different elevations along the longitudinal direction of the dam on the back slope. When detecting the measuring points on each measuring line, the coil should be kept horizontal, and finally induced electromotive force signals at different elevations and different positions are obtained; when the leakage characteristics are manifested as leakage around the dam, the measuring lines can be arranged at different elevations along the transverse direction of the dam. During each detection, the transmitting coil and the receiving coil are rotated in five directions, and the coil bracket should be kept horizontal when changing the coil angle.

[0063] (8) The number of longitudinal detection lines of the dam is greater than 3, the number of measuring points of the transverse detection lines of the dam is greater than 3, and each measuring point measures at least 3 angles.

[0064] 3. Leakage identification

[0065] (3) When the leakage characteristics are manifested as leakage of the dam body and dam foundation, the water conservancy transient electromagnetic supporting software is used to jointly process the data of each measuring point on each survey line. The processing process includes importing data, modifying channel parameters, correcting interference, and mapping apparent resistivity, so as to obtain the measuring point-voltage curve and apparent resistivity profile of each survey line;

[0066] According to the changing characteristics of the measuring point-voltage curve, determine the leakage anomaly in the horizontal direction;

[0067] According to the change characteristics of the apparent resistivity profile, the leakage anomaly in the vertical direction is determined, and the spatial location information such as the scope, burial depth, and strike direction of the comprehensive low-resistance anomaly area is delineated;

[0068] The apparent resistivity profiles on multiple survey lines are jointly imaged in three dimensions to effectively eliminate false anomalies on a single survey line. Combined with leakage survey data, the spatial distribution area of ​​the leakage channel is outlined, providing a target area for further treatment of reservoir dam hidden dangers.

[0069] (4) When the leakage characteristics show leakage at the dam shoulder, the water conservancy transient electromagnetic supporting software is used to jointly process the data of each angle point at each measuring point. The processing flow includes importing data, modifying channel parameters, correcting interference, and mapping apparent resistivity, so as to obtain the angle-voltage curve and apparent resistivity profile of each measuring point;

[0070] According to the changing characteristics of the angle-voltage curve, determine the leakage anomaly at each measuring angle;

[0071] According to the change characteristics of the apparent resistivity profile, the leakage anomaly along the angle direction is determined, and the spatial location information such as the scope, burial depth, and strike direction of the comprehensive low-resistance anomaly area is delineated;

[0072] The apparent resistivity profiles at multiple angle points are jointly imaged in three dimensions to effectively eliminate false anomalies at a single angle point. Combined with the reservoir dam database, the spatial distribution area of ​​the leakage channel is outlined, providing a target area for further treatment of hidden dangers of the reservoir dam.

[0073] Advantages of the present invention:

[0074] 1. The earth-rock dam leakage diagnosis device of the present invention adopts a transmitting coil to supply transient pulses to the dam, and a receiving coil to measure the secondary field signal. The on-site detection system is flexible and easy to operate. There is no need to consider the problems of dam hardening and limited detection space, and it is suitable for multiple dam types such as earth-rock dams and gravity dams.

[0075] 2. During transient electromagnetic detection, the distance between each measuring point on the measuring line can be flexibly adjusted to effectively control the density of measuring points at different locations, and realize the general and detailed investigation of different locations; the size of each angle on the measuring point can also be flexibly adjusted to effectively control the angle density of different measuring points, and realize the general and detailed investigation of different measuring points;

[0076] 3. The transient electromagnetic method collects the secondary field attenuation signal in the normal direction of the coil, has strong directivity to the hidden danger point, and has high lateral resolution;

[0077] 4. Three-dimensional imaging of multiple measuring points on different measuring lines and three-dimensional imaging of multiple angles at different measuring points can effectively improve the reliability of detection and outline the spatial location information of the leakage channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 Schematic diagram of a leakage diagnosis device for earth-rock dam based on transient electromagnetic method.

[0079] Figure 2 This is the traction cross-section of the coil support.

[0080] Figure 3 is a schematic diagram of the cross section in the middle of the b and d sides.

[0081] Figure 4 is a cross-sectional diagram of the support rod.

[0082] Figure 5 is a three-dimensional schematic diagram of the support body,

[0083] Figure 6 Schematic diagram of the cross section of the guide rod;

[0084] Figure 7 is a schematic diagram of the longitudinal section of the guide rod;

[0085] Figure 8 It is a schematic diagram of the combined structure of the support rod and the guide rod;

[0086] Fig. 9 is a schematic diagram of the longitudinal section of the rotating shaft;

[0087] Fig.10 It is a schematic diagram of the connection between the guide rod, the rotating rod, the transmitting coil and the receiving coil;

[0088] Fig.11 4 is a general flow chart of the method used in the embodiment of the present invention.

[0089] 1-hollow circular tube; 2-drag rope; 3-traction ring; 4-coil bracket; 5-support rod; 6-guide rod; 7-semicircle ring; 8-fixed rod; 9-wear-resistant plastic; 10-bearing; 11-small pulley; 12-pad; 13-rotating rod; 14-fixed shaft; 15-transmitting coil; 16-receiving coil; 17-transmitting cable; 18-receiving cable; 19-wireless transmitter; 20-transient electromagnetic host; 21-data control platform; 22-level; 23-tie strip. DETAILED DESCRIPTION

[0090] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "inside" and "outside" indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so the terms describing the positional relationship in the accompanying drawings are only used for illustrative purposes and cannot be understood as a limitation on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0091] First, the present invention provides a leakage diagnosis device for earth-rock dam based on transient electromagnetic:

[0092] A leakage diagnosis device for earth-rock dam based on transient electromagnetic method comprises a coil support 4 formed by enclosing sides a, b, c and d, wherein the structures of the sides b and d of the coil support are arranged symmetrically, the side b of the coil support has a hollow structure (the hollow structure can be a long groove opened along the length direction of the side b), and a support rod 5 and a guide rod 6 are arranged in sequence from the outside to the inside of the hollow structure, and a semicircular ring 7 is fixedly installed at one end of the support rod 5, and the fixed rod 8 passes through the semicircular ring component 7. Therefore, one end of the support rod 5 is rotatably installed in the hollow structure through the fixed rod 8, the support rod can rotate around the fixed rod and can move back and forth on the fixed rod 8, and the fixed rod can move back and forth along the length direction of the hollow structure of the side b. The guide rod 6 is arranged above the support rod 5, and a small pulley 11 is connected to the lower part of one end of the guide rod 6, and the small pulley is fixed on a bearing 10, and the bearing 10 is installed on the coil support, and the guide rod 6 can rotate in the direction of 0-90 degrees through the small pulley. The guide rod 6 is provided with a plurality of marks, and the support rod 5 supports the corresponding mark positions, so that the angle between the guide rod and the ground can be adjusted.

[0093] The coil support c side also has a hollow structure, in which a rotating rod 13 is placed, and both ends of the rotating rod 13 are installed on the coil support c side through a fixed shaft 14; a towing mechanism for dragging the coil support to move is installed on the coil support a side, and the towing mechanism includes a towing rope 2, and both ends of the towing rope 2 are fixed on the coil support a side through a towing ring 3.

[0094] A transmitting coil and a receiving coil are also installed on the inner side of the coil support; the transmitting coil, the receiving coil, the guide rod 6 and the rotating rod 13 are fixed on a plane by a tie bar 23, such as Fig.10 shown.

[0095] A level 22 is installed on the surface of the coil support a side, and a layer of wear-resistant plastic 9 is fixed on the lower surface of the coil support. Preferably, a cushion block 12 is installed in the hollow structure of the coil support b side and below the guide rod, which is used to support the guide rod to be placed horizontally.

[0096] The earth-rock dam leakage diagnosis device also includes a transient electromagnetic host 20, the transmitting coil 15 is connected to the transient electromagnetic host through a transmitting cable, and the receiving coil 16 is connected to the transient electromagnetic host through a receiving cable; the electromagnetic host is connected to the data control platform through a wireless transmitter.

[0097] The hollow circular tube 1, the towing rope 2, the coil support 4, the wear-resistant plastic 9, the transmitting coil 15, the receiving coil 16, the transmitting cable 17, the receiving cable 18, and the level 22 in the device are combined into a modular structure. The towing rope 2 passes through the hollow circular tube 1 and tows the coil support 4 fixed on the wear-resistant plastic 9 through the towing ring 3 to move on the dam. The transmitting coil 15, the receiving coil 16, and the level 22 are fixedly mounted on the coil support 4, and the transmitting coil 15 is connected to the transmitting cable 17, and the receiving coil 16 is connected to the receiving cable 18.

[0098] A support rod 5, a guide rod 6, a ring 7, a fixed rod 8, a bearing 10, a small pulley 11, a cushion block 12, a rotating rod 13, a fixed shaft 14, and a spirit level 22 are fixed on the coil bracket 4. The support rod 5 moves left and right on the fixed rod 8 through the ring 7, thereby adjusting the angle between the guide rod 6 and the horizontal plane. One end of the fixed rod 8 is connected to the small pulley 11 fixed on the bearing 10, and can rotate freely in the vertical direction of 0 to 90 degrees. A cushion block 12 is fixed below the middle of the guide rod 6; both ends of the rotating rod 13 are inserted into the fixed shaft 14, thereby ensuring that the rotating rod 13 can rotate freely; the guide rod 6, the rotating rod 13 on the coil bracket 4 and the transmitting coil 15 and the receiving coil 16 are fixed to the same plane by a tie strip 23.

[0099] A method for using a leakage diagnosis device for earth-rock dam based on transient electromagnetic method, the specific working method is as follows:

[0100] 1. Leakage investigation

[0101] (1) Visit the three responsible persons of the reservoir dam and the surrounding villagers to learn about the engineering data during the reservoir construction period, including the source of the dam filling materials, the dam type, whether the dam foundation is in the bedrock, and whether there are any abnormal phenomena during the construction process;

[0102] (2) Collect historical data on reservoir reinforcement over the years, including safety appraisal, engineering geological survey, risk elimination and reinforcement design, and construction data;

[0103] (3) Conduct a site survey of the reservoir to investigate the spatial location of the leakage point, the turbidity of the water body, the apparent characteristics of the dam, and the relationship between the leakage amount and the reservoir water level;

[0104] (4) Integrate the above survey data into the reservoir dam database.

[0105] 2. Hidden danger detection

[0106] (1) When the leakage characteristics are manifested as leakage of the dam body and dam foundation, the earth-rock dam leakage diagnosis device is arranged on the anti-seepage section of the dam top. During detection, the dam top is marked from left to right at intervals of 1m, with a distance of 0.5m from the left dam head as the starting point; the center point of the coil support 4 is coincident with the starting point of the survey line, ensuring that the level 22 on the coil support 4 is in a horizontal state, the transmitting coil 15 is connected to the transient electromagnetic host 20 through the transmitting cable 17, the receiving coil 16 is connected to the transient electromagnetic host 20 through the receiving cable 18, and the transient electromagnetic host 20 is connected to the data control platform 21 through the wireless transmitter 19 agreed on by the network, and the number of turns of the transceiver coil, the transmitting frequency, the transmitting current, the number of superpositions, the measurement mode and other parameters are adjusted on the data control platform 21. After the parameter settings are received, the data control platform 21 sends a collection command to the transient electromagnetic host 20, and the secondary field signal collected in the transient electromagnetic host 20 is recovered; after the collection of a single measuring point is completed, the coil support is pulled by the towing rope 2 to move the position of the device in sequence at intervals of 1m, and the data collection and recovery are completed at each measuring point on the survey line, so that the induced electromotive force signal of the dam at different positions on a single section can be obtained;

[0107] (2) When the leakage characteristics show leakage around the dam, the earth-rock dam leakage diagnosis device is arranged on the dam head closest to the leakage point. During detection, the transient electromagnetic coil bracket 4 is horizontally placed at the dam head position to ensure that the level 22 on the coil bracket 4 is in a horizontal state, the transmitting coil 15 is connected to the transient electromagnetic host 20 through the transmitting cable 17, the receiving coil 16 is connected to the transient electromagnetic host 20 through the receiving cable 18, and the transient electromagnetic host 20 is connected to the data control platform 21 through the wireless sensor 19 agreed on by the network. The number of turns of the transceiver coil, the transmitting frequency, the transmitting current, the number of superpositions, the measurement mode and other parameters are adjusted on the data control platform 21. After the parameter settings are received, the data control platform 21 sends a collection command to the transient electromagnetic host 20 and performs a transient electromagnetic measurement. The secondary field signal collected in the electromagnetic host 20 is recovered; when the coil horizontal signal is collected, the support rod 5 is used to support the marking position of the guide rod 6, and the angle between the guide rod and the horizontal plane can be adjusted to 15°, so as to control the plane normal of the guide rod 6 to point to the dam shoulder. The data control platform 21 sends a collection command to the transient electromagnetic host 20, and recovers the secondary field signal collected in the transient electromagnetic host 20. The angle between the guide rod 6 and the ground can be adjusted to 30°, 45°, 60°, and 90° in turn. The data collection and recovery are completed at each measuring point on the survey line, and the induced electromotive force signals of different directions of the dam shoulder on a single section can be obtained;

[0108] (3) After the dam top detection in step 1) and step 2) is completed, when the leakage characteristics are manifested as leakage of the dam body and dam foundation, the earth-rock dam leakage diagnosis device can arrange detection lines at different elevations along the longitudinal direction of the dam on the back slope. When detecting the measuring points on each measuring line, the coil should be kept horizontal, and finally the induced electromotive force signals at different elevations and different positions are obtained; when the leakage characteristics are manifested as leakage around the dam, the measuring lines can be arranged at different elevations along the transverse direction of the dam. During each detection, the transmitting coil and the receiving coil are rotated in five directions, and the coil support should be kept horizontal when the coil angle is changed;

[0109] (4) The number of longitudinal detection lines of the dam is greater than 3, the number of measuring points of the transverse detection lines of the dam is greater than 3, and each measuring point measures at least more than 3 angles.

[0110] 3. Leakage identification

[0111] (1) When the leakage characteristics are manifested as leakage of the dam body and dam foundation, the water conservancy transient electromagnetic supporting software is used to jointly process the data of each measuring point on each survey line. The processing process includes importing data, modifying channel parameters, correcting interference, and mapping apparent resistivity, so as to obtain the measuring point-voltage curve and apparent resistivity profile of each survey line;

[0112] According to the changing characteristics of the measuring point-voltage curve, determine the leakage anomaly in the horizontal direction;

[0113] According to the change characteristics of the apparent resistivity profile, the leakage anomaly in the vertical direction is determined, and the spatial location information such as the scope, burial depth, and strike direction of the comprehensive low-resistance anomaly area is delineated;

[0114] The apparent resistivity profiles on multiple survey lines are jointly imaged in three dimensions to effectively eliminate false anomalies on a single survey line. Combined with leakage survey data, the spatial distribution area of ​​the leakage channel is outlined, providing a target area for further treatment of reservoir dam hidden dangers.

[0115] (2) When the leakage characteristics show leakage at the dam shoulder, the water conservancy transient electromagnetic supporting software is used to jointly process the data of each angle point at each measuring point. The processing flow includes importing data, modifying channel parameters, correcting interference, and mapping apparent resistivity, so as to obtain the angle-voltage curve and apparent resistivity profile of each measuring point;

[0116] According to the changing characteristics of the angle-voltage curve, determine the leakage anomaly at each measuring angle;

[0117] According to the change characteristics of the apparent resistivity profile, the leakage anomaly along the angle direction is determined, and the spatial location information such as the scope, burial depth, and strike direction of the comprehensive low-resistance anomaly area is delineated;

[0118] The apparent resistivity profiles at multiple angle points are jointly imaged in three dimensions to effectively eliminate the false anomalies at a single angle point. Combined with the reservoir dam database, the spatial distribution area of ​​the leakage channel is outlined, providing a target area for further treatment of reservoir dam hidden dangers.

Claims

1. A leakage diagnosis device for earth-rock dam based on transient electromagnetic method, comprising a coil support surrounded by sides a, b, c and d, characterized in that: The structures of the b side and the d side of the coil support are arranged symmetrically. The b side of the coil support has a hollow structure, and a support rod and a guide rod are arranged in sequence from the outside to the inside of the hollow structure. One end of the support rod is rotatably installed in the hollow structure of the b side of the coil support through a fixed rod, and the support rod can rotate around the fixed rod and can move back and forth on the fixed rod, and the fixed rod can move back and forth along the length direction of the hollow structure of the b side of the coil support; the guide rod is arranged above the support rod and one end of the guide rod is rotatably installed on the b side of the coil support through a rotating mechanism; the c side of the coil support also has a hollow structure and a rotating rod is rotatably installed therein; the a side of the coil support is provided with a towing mechanism for towing the coil support to move; a transmitting coil and a receiving coil are provided on the inner side of the coil support; the transmitting coil, the receiving coil, the guide rod and the rotating rod are fixed on a plane through a fixing member; a number of marks are provided on the guide rod, and the support rod supports the corresponding mark positions for adjusting the angle between the guide rod and the ground.

2. The earth-rock dam leakage diagnosis device according to claim 1, characterized in that: The fixing rod is arranged away from the rotating mechanism; the end of the supporting rod has a semicircular ring, and the fixing rod passes through the semicircular ring.

3. The earth-rock dam leakage diagnosis device according to claim 1, characterized in that: The rotating mechanism includes a small pulley and a bearing; a small pulley is connected to the lower part of one end of the guide rod, the small pulley is fixed on the bearing, and the bearing is installed on the coil bracket. The guide rod can rotate in the direction of 0-90° through the small pulley.

4. The earth-rock dam leakage diagnosis device according to claim 1, characterized in that: A level is installed on the surface of the coil support side a, and a layer of wear-resistant plastic is fixed around the lower surface of the coil support.

5. The earth-rock dam leakage diagnosis device according to claim 1, characterized in that: A cushion block is also installed in the hollow structure on the coil support b side and below the guide rod, and is used to support the guide rod to be placed horizontally.

6. The earth-rock dam leakage diagnosis device according to claim 1, characterized in that: The towing mechanism comprises a towing rope, both ends of which are fixed on the edge of the coil support a through a towing ring.

7. The earth-rock dam leakage diagnosis device according to any one of claims 1 to 6, characterized in that: It also includes a transient electromagnetic host, the transmitting coil is connected to the transient electromagnetic host through a transmitting cable, and the receiving coil is connected to the transient electromagnetic host through a receiving cable; the electromagnetic host is connected to the data control platform through a wireless transmitter.

8. The method for using the earth-rock dam leakage diagnosis device according to claim 7, characterized in that: The steps include: Step 1: Leakage Survey (1) Visit the three responsible persons of the reservoir dam and the surrounding villagers to learn about the engineering data during the reservoir construction period, including the source of the dam filling materials, the dam type, whether the dam foundation is in the bedrock, and whether there are any abnormal phenomena during the construction process; (2) Collect historical data on reservoir reinforcement over the years, including safety appraisal, engineering geological survey, risk elimination and reinforcement design, and construction data; (3) Conduct a site survey of the reservoir to investigate the spatial location of the leakage point, the turbidity of the water body, the apparent characteristics of the dam, and the relationship between the leakage amount and the reservoir water level; (4) Integrate the above survey data into a reservoir dam database; Step 2: Hazard detection (1) When the leakage characteristics are manifested as leakage of the dam body and dam foundation, the earth-rock dam leakage diagnosis device is arranged on the anti-seepage section of the dam top; during detection, the dam top is marked from left to right at intervals of 1m, with a distance of 0.5m from the left dam head as the starting point; the center point of the coil bracket is coincident with the starting point of the survey line to ensure that the coil is in a horizontal state, the transmitting coil is connected to the transient electromagnetic host through a transmitting cable, the receiving coil is connected to the transient electromagnetic host through a receiving cable, and the transient electromagnetic host is connected to the data control platform through a wireless transmitter agreed on the network. The number of turns of the transmitting and receiving coils, the transmitting frequency, the transmitting current, the number of superpositions, and the measurement mode parameters are adjusted on the data control platform. After the parameter settings are received, the data control platform sends a collection command to the transient electromagnetic host and recovers the secondary field signal collected in the transient electromagnetic host; after the collection of a single measuring point is completed, the position of the device is moved in sequence according to the interval of 1m, and each measuring point on the survey line completes the data collection and recovery, so that the induced electromotive force signal of the dam at different positions on a single section can be obtained; (2) When the leakage characteristics show leakage around the dam, the earth-rock dam leakage diagnosis device is arranged on the dam head closest to the leakage point; during detection, the coil bracket is horizontally placed at the dam head position to ensure that the level gauge on the coil bracket is in a horizontal state, the transmitting coil is connected to the transient electromagnetic host through the transmitting cable, the receiving coil is connected to the transient electromagnetic host through the receiving cable, and the transient electromagnetic host is connected to the data control platform through the wireless sensor agreed on by the network. The number of turns of the transmitting and receiving coils, the transmitting frequency, the transmitting current, the number of superpositions, and the measurement mode parameters are adjusted on the data control platform. After the parameter settings are received, the data control platform sends a signal to the transient electromagnetic The host sends a collection command and recycles the secondary field signal collected in the transient electromagnetic host; when the coil horizontal signal is collected, the support rod is used to support the marked position of the guide rod, and the angle between the guide rod and the horizontal plane is adjusted to 15°, so as to control the plane normal of the guide rod to point to the dam shoulder. The data control platform sends a collection command to the transient electromagnetic host and recycles the secondary field signal collected in the transient electromagnetic host, and adjusts the angle between the guide rod and the ground to 30°, 45°, 60° or 90° in turn. The data collection and recovery are completed at each measuring point on the survey line, and the induced electromotive force signals of different directions of the dam shoulder on a single section can be obtained; (3) After the dam top detection of step (1) and step (2) is completed, when the leakage characteristics are manifested as leakage of the dam body and dam foundation, the earth-rock dam leakage diagnosis device arranges detection lines at different elevations along the longitudinal direction of the dam on the back slope, and the coil should be kept horizontal when detecting the measuring points on each measuring line, and finally obtains induced electromotive force signals at different elevations and different positions; when the leakage characteristics are manifested as leakage around the dam, the measuring lines are arranged at different elevations along the transverse direction of the dam, and the transmitting coil and the receiving coil are kept rotating in five directions during each detection, and the coil support should be kept horizontal when changing the coil angle; (4) The number of longitudinal survey lines of the dam is greater than 3, the number of measuring points of the transverse survey line of the dam is greater than 3, and each measuring point measures at least 3 angles; Step 3: Leakage Identification (1) When the leakage characteristics are manifested as leakage of the dam body and dam foundation, the water conservancy transient electromagnetic supporting software is used to jointly process the data of each measuring point on each survey line. The processing process includes importing data, modifying channel parameters, correcting interference, and mapping apparent resistivity, so as to obtain the measuring point-voltage curve and apparent resistivity profile of each survey line; According to the changing characteristics of the measuring point-voltage curve, determine the leakage anomaly in the horizontal direction; According to the change characteristics of the apparent resistivity profile, the leakage anomaly in the vertical direction is determined, and the scope, burial depth, and spatial location information of the low-resistance anomaly area are delineated; Conduct joint 3D imaging of apparent resistivity profiles on multiple survey lines to effectively eliminate false anomalies on a single survey line. Combined with leakage survey data, the spatial distribution area of ​​the leakage channel can be outlined to provide target areas for further treatment of reservoir dam hidden dangers. (2) When the leakage characteristics show leakage at the dam shoulder, the water conservancy transient electromagnetic supporting software is used to jointly process the data of each angle point at each measuring point. The processing flow includes importing data, modifying channel parameters, correcting interference, and mapping apparent resistivity, so as to obtain the angle-voltage curve and apparent resistivity profile of each measuring point; According to the changing characteristics of the angle-voltage curve, determine the leakage anomaly at each measuring angle; According to the change characteristics of the apparent resistivity profile, the leakage anomaly along the angle direction is determined, and the scope, burial depth, and spatial location information of the low-resistance anomaly area are delineated; The apparent resistivity profiles at multiple angle points are jointly imaged in three dimensions to effectively eliminate false anomalies at a single angle point. Combined with the reservoir dam database, the spatial distribution area of ​​the leakage channel is outlined, providing a target area for further treatment of hidden dangers of the reservoir dam.

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