CN-122016176-A - Mine tailing pond leakage detection method and system based on resistivity tomography

CN122016176ACN 122016176 ACN122016176 ACN 122016176ACN-122016176-A

Abstract

The invention belongs to the technical field of mine safety and environmental monitoring, and particularly relates to a mine tailing pond leakage detection method and system based on resistivity tomography. The method comprises the steps of embedding electrodes in a dam body of a tailing pond according to a layering and partitioning principle to form a distributed three-dimensional electrode array, arranging penetrating electrodes in an area below an impermeable layer by penetrating the impermeable layer through a sealing sleeve, performing reference measurement on the electrodes of the whole array, obtaining three-dimensional background resistivity and background polarizability distribution of the dam body through joint inversion, and recording the background resistivity and the background polarizability into a database to serve as differential monitoring references. According to the invention, the spatial position, thickness and resistivity of the impermeable layer are used as strong priori constraints to be fused into the joint inversion objective function, and the penetrating electrode is arranged below the impermeable layer, so that the detection capability of the area below the impermeable layer is doubly enhanced from the acquisition end and the inversion end, and the problem of deep signal distortion caused by the high-resistance impermeable layer in the prior art is solved.

Inventors

MENG CHEN
WANG LEI
YUE JIANMIN
ZHANG XUE

Assignees

宁夏大学

Dates

Publication Date: 20260512
Application Date: 20260309

Claims (10)

1. The mine tailing pond seepage detection method based on resistivity tomography is characterized by comprising the following steps of: Pre-burying electrodes in a dam body of a tailing pond according to a layering and partitioning principle to form a distributed three-dimensional electrode array, penetrating the penetrating electrodes below the impermeable layer through a sealing sleeve, and performing reference measurement on the electrodes of the whole array, wherein the reference measurement and the subsequent periodic monitoring measurement are both obtained by adopting the same acquisition mode that a multi-frequency current transmitter inputs multi-frequency pseudo-random waveform current and a multi-channel receiver synchronously acquires potential difference time sequences, and the three-dimensional background resistivity of the dam body is obtained through joint inversion And background polarization rate The distribution, the background resistivity and the background polarization rate are recorded into a database to be used as a differential monitoring reference; Inputting a multi-frequency pseudo-random waveform current with the frequency range of 0.01Hz to 100Hz to the power supply electrode pair through a multi-frequency current transmitter, synchronously collecting potential difference time sequences of all the measuring electrode pairs through a multi-channel receiver, carrying out Fourier transformation on the potential difference time sequences to extract complex impedance under all the frequencies, and calculating the apparent resistivity of all the measuring points according to the complex impedance Visual polarizability Obtaining a multi-parameter observation data set; Determining the space position, thickness and resistivity range of an impermeable layer according to design data of a tailing pond, endowing a grid unit where the impermeable layer is positioned with high initial resistivity and setting strong constraint weight in a three-dimensional inversion grid, and taking the logarithmic values of the resistivity and the polarizability as a parameter vector of a joint model Constructing a joint inversion objective function containing an impermeable layer priori constraint term and an excitation dual-parameter fitting term, and solving by adopting an iterative algorithm to obtain the three-dimensional resistivity of the dam at the current moment And polarization rate Distribution; comparing the resistivity and the polarization ratio distribution obtained by the current inversion with a background field, and calculating time sequence differential resistivity And time sequence differential polarization rate The differential result is subjected to triple judgment by sequentially applying an amplitude criterion, a spatial continuity criterion and a time continuity criterion, and the area meeting the triple criterion is judged to be a leakage abnormal area; and carrying out three-dimensional reconstruction on the determined leakage abnormal region by adopting a kriging interpolation method to obtain a three-dimensional coordinate range and a spatial form of the leakage channel, tracking a pollution feather diffusion range according to the spatial distribution of the abnormal region with high polarizability, calculating a leakage scale comprehensive evaluation index according to a comprehensive differential resistivity reduction amplitude, a differential polarizability increase amplitude and an abnormal body spatial range, and triggering corresponding level early warning according to the leakage scale comprehensive evaluation index and leakage expansion rate.
2. The mine tailing pond seepage detection method based on resistivity tomography according to claim 1, wherein the forming of the distributed three-dimensional electrode array by pre-burying the electrodes in the tailing pond dam body according to the principle of layering and partitioning comprises the following steps: the method comprises the steps of arranging a plurality of monitoring layers along the height direction of a dam body, determining the burying depth of each layer of electrode according to the design position of a dam body infiltration line, the spatial position of an impermeable layer and the historical seepage risk evaluation, uniformly arranging electrodes in each monitoring layer along the axial direction of the dam and the axial direction of a perpendicular dam to form a two-dimensional grid according to preset electrode intervals, and carrying out electrode encryption arrangement on the contact surface of a dam toe, a dam foundation and the dam body and the damage risk area of the impermeable layer to obtain a three-dimensional electrode array network covering the whole section of the dam body.
3. The mine tailing pond leakage detection method based on resistivity tomography according to claim 1, wherein the apparent resistivity of each measuring point is calculated according to complex impedance Visual polarizability Comprising the following steps: According to the formula Calculating apparent resistivity, wherein As a function of the device coefficients, For the total potential difference to be the same, For supplying current according to the formula Calculating the visual polarization rate, wherein For the secondary field potential difference after power-off, And combining the apparent resistivity and the apparent polarization rate at each frequency to obtain a multi-parameter observation data set.
4. The method for detecting leakage of mine tailings pond based on resistivity tomography according to claim 1, wherein the constructing the joint inversion objective function comprising the impermeable layer prior constraint term and the excitation double parameter fitting term comprises: setting initial resistivity of a grid unit where an impermeable layer is located, setting priori variance of an impermeable layer area to be a small value to form strong constraint weight, and constructing a joint inversion objective function as follows: ; Wherein the method comprises the steps of And The observed apparent resistivity and apparent polarizability data vectors, And The forward operators of resistivity and polarizability respectively, In the form of a smoothness matrix, As a priori model of the high resistivity values of the barrier, For the matrix of the weights a priori, To balance the factors of resistivity and polarizability data weights, In order to a priori constrain the intensity factor, Adopting Gaussian-Newton method to make iterative solution until the data fitting residual error is reduced below preset threshold value so as to obtain the three-dimensional resistivity of dam body at current moment And polarization rate Distribution.
5. The method for detecting leakage of mine tailing pond based on resistivity tomography as set forth in claim 1, wherein the calculating time-series differential resistivity And time sequence differential polarization rate Comprising the following steps: According to the formula Calculating time sequence differential resistivity according to the formula Calculating time sequence differential polarization rate, wherein And The background resistivity and the background polarization rate respectively, And And inverting the obtained resistivity and the obtained polarizability at the current moment respectively.
6. The method for detecting leakage of mine tailings pond based on resistivity tomography according to claim 1, wherein the triple discrimination of the differential result by sequentially applying an amplitude criterion, a spatial continuity criterion and a time continuity criterion comprises: Differential resistivity with time sequence Time sequence differential polarization rate lower than preset negative threshold and in same area The method comprises the steps of marking a region higher than a preset positive threshold as a candidate region meeting an amplitude criterion, carrying out space continuity detection on the candidate region meeting the amplitude criterion, reserving a connected region with a continuous volume larger than or equal to the preset volume threshold as a region meeting the space continuity criterion, filtering isolated noise points which do not meet the minimum continuous volume, carrying out time continuity detection on the region meeting the space continuity criterion, judging the region which continuously exists in a plurality of continuous measurement periods and shows an expansion trend as a leakage abnormal region, and eliminating the candidate region which only appears in single measurement.
7. The mine tailing pond seepage detection method based on resistivity tomography according to claim 1, wherein triggering the corresponding level early warning according to the seepage scale comprehensive evaluation index and the seepage expansion rate comprises: The method comprises the steps of establishing a three-level early warning system according to a leakage scale comprehensive evaluation index, triggering a blue primary early warning when an abnormal scale is small and is slow to expand, encrypting and monitoring frequency and performing manual rechecking, triggering a yellow secondary early warning when the abnormal scale reaches a certain level and is in a continuous expansion trend, starting special investigation and making an emergency plan, triggering a red three-level early warning when the abnormal scale is large and is rapid to expand and dam safety risks exist, starting an emergency response program, and pushing early warning signals of all levels to a tailing pond safety management platform in real time to trigger corresponding emergency response processes.
8. A mine tailing pond seepage detection system based on resistivity tomography, which is characterized by comprising a pre-buried distributed three-dimensional electrode array module, a multi-frequency data acquisition and transmission module, a resistivity-polarizability joint inversion module containing impermeable layer priori constraint, a dynamic differential monitoring and multidimensional anomaly identification module and a seepage three-dimensional positioning and grading early warning module which are sequentially connected, wherein the method is as claimed in any one of claims 1 to 7; The embedded distributed three-dimensional electrode array module comprises corrosion-resistant electrodes embedded in a dam body according to a layering and partitioning principle and penetrating electrodes penetrating through an impermeable layer, wherein the penetrating electrodes penetrate through the impermeable layer by adopting a sealing sleeve and are subjected to waterproof sealing treatment, and the electrodes are connected to a dam top control box through a multi-core cable; the multi-frequency data acquisition and transmission module comprises a multi-frequency current transmitter and a multi-channel receiver, wherein the multi-frequency current transmitter inputs multi-frequency pseudo-random waveform current with the frequency range of 0.01Hz to 100Hz to the power supply electrode, and the multi-channel receiver synchronously acquires multi-frequency complex potential difference responses of each measuring electrode pair and transmits data to the data processing center in real time; The resistivity-polarizability joint inversion module containing the impermeable layer priori constraint is used for establishing an initial electric model according to impermeable layer priori information, and carrying out three-dimensional joint inversion on observed data by using a joint inversion objective function containing an impermeable layer strong priori constraint item and an excitation double-parameter fitting item to obtain underground three-dimensional resistivity and polarizability distribution; the dynamic differential monitoring and multidimensional anomaly identification module is used for calculating a time sequence differential quantity from a current inversion result and a background field, and carrying out triple discrimination on the differential result by combining an amplitude criterion, a space continuity criterion and a time continuity criterion to identify a leakage anomaly area; And the leakage three-dimensional positioning and grading early warning module is used for carrying out three-dimensional space reconstruction and pollution plume tracking on the leakage abnormal region, triggering three-level early warning according to the leakage scale comprehensive evaluation index and pushing the three-level early warning to the safety management platform.
9. The mine tailing pond seepage detection system based on resistivity tomography according to claim 8, wherein the corrosion-resistant electrode is made of titanium alloy or platinum iridium alloy material, the multi-frequency current transmitter supports electrode combination forms of a winker device, a Shi Lunbei Xie Zhuangzhi and a dipole-dipole device, the data acquisition is automatically executed according to a preset period under normal working conditions, and the data acquisition is automatically switched to a high-frequency encryption acquisition mode when the abnormal identification module triggers an early warning signal.
10. The mine tailing pond seepage detection system based on resistivity tomography according to claim 8, wherein the seepage three-dimensional positioning and grading early warning module is further used for automatically generating a comprehensive detection report including a three-dimensional resistivity and polarizability distribution diagram, a differential abnormal region three-dimensional rendering diagram, a seepage channel shape and coordinate, a pollution plume range and an early warning state at regular intervals.

Description

Mine tailing pond leakage detection method and system based on resistivity tomography Technical Field The invention belongs to the technical field of mine safety and environmental monitoring, and particularly relates to a mine tailing pond leakage detection method and system based on resistivity tomography. Background The mine tailing pond is a special piling facility for mineral dressing waste and waste liquid, and the dam body bears hydrostatic pressure and hydrodynamic pressure for a long time and is easy to develop a seepage passage inside. The dam material can be softened by the leakage water to cause piping and even dam break, and the lead, cadmium, arsenic and other heavy metal ions in the waste liquid enter soil and aquifer to cause long-term environmental pollution, so that the early detection and the accuracy have great engineering significance. At present, the leakage detection of the tailing pond mainly depends on traditional methods such as manual inspection, drilling sampling, osmometer observation and the like, and has the defects of large detection blind area, limited layout, incapability of three-dimension and the like. With the development of nondestructive testing technology, geophysical methods such as resistivity tomography and the like are applied to dam leakage detection, but the method still has outstanding limitations when the method is directly applied to a tailing pond, a high-resistance impermeable layer such as an HDPE geomembrane is usually paved at the bottom of the tailing pond, current of a conventional resistivity method is difficult to penetrate through the high-resistance layer, a deep leakage channel signal below the impermeable layer is extremely weak, an inversion result is seriously distorted, and no targeted treatment is performed on the shielding effect by the conventional method. In addition, the existing electrical detection method only depends on single resistivity parameters, but the water leakage of the tailing pond is rich in metal ions and sulfides, obvious excitation effect is generated under an alternating electric field, the clay interlayer has distinct polarizability responses although the clay interlayer is also low-resistance, the water-containing leakage area and the low-resistance geological anomalies cannot be effectively distinguished only by the resistivity, and a large amount of false interpretation risks exist. Disclosure of Invention (1) Technical problem to be solved The invention aims to provide a mine tailing pond seepage detection method and system based on resistivity tomography, which are used for solving the problem that a large number of false interpretation risks exist because a water-containing seepage region cannot be effectively distinguished from a low-resistance geological anomaly only by relying on a single resistivity parameter. (2) Technical proposal In order to achieve the above object, in one aspect, the present invention provides a mine tailing pond seepage detection method based on resistivity tomography, comprising: Pre-burying electrodes in a dam body of a tailing pond according to a layering and zoning principle to form a distributed three-dimensional electrode array, arranging penetrating electrodes below an impermeable layer by penetrating the impermeable layer through a sealing sleeve, performing reference measurement on the electrodes of the whole array, and obtaining the three-dimensional background resistivity of the dam body through joint inversion And background polarization rateAnd (3) distributing, namely recording the background resistivity and the background polarization ratio into a database to serve as a differential monitoring reference. Inputting a multi-frequency pseudo-random waveform current with the frequency range of 0.01Hz to 100Hz to the power supply electrode pair through a multi-frequency current transmitter, synchronously collecting potential difference time sequences of all the measuring electrode pairs through a multi-channel receiver, carrying out Fourier transformation on the potential difference time sequences to extract complex impedance under all the frequencies, and calculating the apparent resistivity of all the measuring points according to the complex impedanceVisual polarizabilityA multi-parameter observation dataset is obtained. Determining the space position, thickness and resistivity range of an impermeable layer according to design data of a tailing pond, endowing a grid unit where the impermeable layer is positioned with high initial resistivity and setting strong constraint weight in a three-dimensional inversion grid, and taking the logarithmic values of the resistivity and the polarizability as a parameter vector of a joint modelConstructing a joint inversion objective function containing an impermeable layer priori constraint term and an excitation dual-parameter fitting term, and solving by adopting an iterative algorithm to obtain the three-dimensional resistivity of the da