In-well coupling electric field accurate positioning technology for thick heap landfill leakage

Abstract

The invention relates to the technical field of landfill leakage point positioning, in particular to a well coupling electric field accurate positioning technology for thick pile landfill leakage. A plurality of well positions are arranged in the landfill for drilling, and a plurality of drilled wells are obtained; direct-current electric fields are applied to the top and the bottom of the landfill, and the voltage of each drilling well is measured; establishing a distribution curve according to the voltage of each drilling well, and sequentially obtaining a set number of minimum value points in the distribution curve; and according to the well drilling fitting polygons corresponding to the minimum value points with the set number, the gravity center of the fitting polygons is obtained, and the leakage points of the landfill are obtained. The detection method provided by the invention can adapt to landfills with different thicknesses and different structures, is particularly suitable for leakage detection of a thick-heap landfill, can effectively penetrate through a thick-layer landfill, and can accurately position damage of an underground impermeable layer.

Description

Technical Field

[0001] The present invention relates to the technical field of landfill leakage point positioning, and in particular to a well-coupled electric field precise positioning technology for thick landfill leakage. Background Art

[0002] With the acceleration of urbanization, landfills have become the main way to dispose of solid waste. Over time, the impermeable layer at the bottom of the landfill may be damaged due to external factors or expiration of its service life, causing leakage of harmful substances and polluting the surrounding soil and groundwater. Therefore, how to quickly and accurately locate the leakage has become an important issue in environmental protection and governance.

[0003] Existing landfill leakage detection technologies mainly rely on surface monitoring or the use of surface electrical measurement methods in electrical exploration. Although these methods are effective in shallow layers or thin piles, when faced with landfills with thick piles, the electrical signals are often shielded by the thick layer of landfill and cannot accurately penetrate the impermeable layer, resulting in poor positioning effects and low detection accuracy and efficiency of the leakage location. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a coupled electric field precise positioning technology in a well for leakage in a thick landfill. The scheme includes: setting up multiple well positions in the landfill for drilling to obtain multiple wells; applying a DC electric field to the top and bottom of the landfill, and measuring the voltage of each well respectively; establishing a distribution curve according to the voltage of each well, and sequentially obtaining a set number of minimum points in the distribution curve; fitting polygons of the wells corresponding to the set number of minimum points, obtaining the center of gravity of the fitting polygon, and obtaining the leakage point of the landfill. The detection method proposed by the present invention can adapt to landfills of different thicknesses and different structures, and is particularly suitable for leakage detection in thick landfills. It can effectively penetrate thick layers of landfill and accurately locate damage to the underground anti-seepage layer.

[0005] The present invention adopts the following technical solution, a well coupling electric field precise positioning technology for leakage in thick landfill, including:

[0006] Setting a plurality of well positions in the landfill for drilling to obtain a plurality of drilled wells;

[0007] A DC electric field was applied to the top and bottom of the landfill and the voltage was measured at each borehole;

[0008] Establish a distribution curve according to the voltage of each well, and obtain a set number of minimum value points in the distribution curve in order from small to large;

[0009] According to the drilling fitting polygons corresponding to the set number of minimum value points, the centroid of the fitting polygon is obtained to obtain the leakage point of the landfill.

[0010] Furthermore, the drilling depth exceeds the garbage dump and does not exceed the impermeable layer.

[0011] Furthermore, the direct current electric field is applied to the top and bottom of the landfill by evenly arranging a plurality of electrodes on the top of the landfill to provide a positive voltage, and the bottom of the landfill is grounded.

[0012] Furthermore, the wellbore is also provided with measuring electrodes and an electric field measuring device for measuring the voltage and vertical electric field component corresponding to each wellbore.

[0013] The beneficial effects of the present invention are as follows: the present invention provides a well-coupled electric field precise positioning technology for leakage in thick landfills, which is adaptable to landfills of different thicknesses and structures, and is particularly suitable for leakage detection in thick landfills. It can effectively penetrate thick layers of landfill and accurately locate damage to underground anti-seepage layers, and can effectively locate leakage points in thick landfills. It has the characteristics of high positioning accuracy, wide detection range, and strong adaptability. Through coupled electric field measurement and analysis, it can accurately locate leakage points in thick landfills, with small positioning errors, and real-time electric field measurement can detect leakage problems at an early stage, reducing the risk of environmental pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0015] Figure 1 It is a schematic diagram of a process flow of a coupled electric field precise positioning technology in a well for leakage in a thick landfill according to an embodiment of the present invention;

[0016] Figure 2 A schematic diagram of a thick landfill drilling layout pattern according to an embodiment of the present invention;

[0017] Figure 3 It is a schematic diagram of a simulation model for accurate positioning of coupled electric fields in wells for leakage in thick landfills according to an embodiment of the present invention;

[0018] Figure 4 This is a simulation result diagram of precise positioning of coupled electric field in a well for leakage in a thick landfill according to an embodiment of the present invention;

[0019] Figure 5This is a simulation result diagram of precise positioning of coupled electric field in a well for leakage in a thick landfill according to an embodiment of the present invention;

[0020] In the figure: 1. Drilling; 2. DC power supply; 3. Electric field measuring device; 4. Measuring electrode. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] A schematic diagram of a process flow of a coupled electric field accurate positioning technology for thick landfill leakage in a well according to an embodiment of the present invention is shown in FIG. Figure 1 As shown, including:

[0023] Setting a plurality of well positions in the landfill for drilling to obtain a plurality of drilled wells;

[0024] A DC electric field was applied to the top and bottom of the landfill and the voltage was measured at each borehole;

[0025] In the embodiment of the present invention, measuring electrodes and an electric field measuring device are arranged in the wellbore to measure the voltage and vertical electric field component corresponding to each wellbore.

[0026] Establish a distribution curve according to the voltage of each well, and obtain a set number of minimum value points in the distribution curve in order from small to large;

[0027] According to the drilling fitting polygons corresponding to the set number of minimum value points, the centroid of the fitting polygon is obtained to obtain the leakage point of the landfill.

[0028] In another embodiment of the present invention:

[0029] like Figure 2 As shown, in an embodiment of the present invention, a plurality of boreholes 1 are arranged in a landfill, and the boreholes penetrate deep into the landfill layer until reaching the impermeable layer. At the same time, measuring electrodes are installed in the boreholes, and an electric field measuring device 3 measures the electric field and vertical electric field component of each borehole through the electrodes in the boreholes. At the same time, the present invention evenly lays a plurality of DC power supplies 2 on the surface of the boreholes, and grounds the impermeable layer of the landfill, thereby forming a DC electric field.

[0030] In the embodiment of the present invention, the arranged drilled well may also be an exhaust hole existing in the landfill, and directly using the exhaust hole for measurement can further improve the positioning efficiency.

[0031] In the embodiment of the present invention, the electric field measuring device may be an electric field measuring instrument, or may be any device capable of receiving electric signals, such as an electric field sensor.

[0032] In the embodiment of the present invention, the depth of the drilling wells arranged in the landfill remains consistent.

[0033] The present invention uses the coupling electric field principle to apply a direct current electric field to the top and bottom of the landfill, measures the voltage distribution and the vertical electric field component in the well, and analyzes the change of the electric field in the vertical direction. In the area where no leakage occurs, the electric field distribution is relatively uniform, while in the leakage area, the electric field forms a loop with the outside world due to the outflow of the leakage liquid, which affects the change of the electric field distribution and causes the voltage amplitude to be relatively reduced. Therefore, by arranging multiple wells in the landfill, the voltage values ​​and the vertical electric field components at different depths in the wells, as well as the voltage values ​​and the vertical electric field components of different well combinations are measured and recorded, and then the voltage change of the electric field in different wells is analyzed to find the minimum value of the voltage. In a specific embodiment of the present invention, taking the polygon as a triangle as an example, the first minimum value, the second minimum value and the third minimum value in the distribution curve are obtained; the center of gravity of the triangle surrounded by the wells corresponding to the first minimum value, the second minimum value and the third minimum value is the predicted leakage point.

[0034] In the embodiment of the present invention, the first minimum value, the second minimum value and the third minimum value are the minimum value, the sub-minimum value and the sub-sub-minimum value obtained in sequence after analyzing the distribution curve. These extreme points are circled to obtain a triangle for determining the leakage point.

[0035] In summary, the present invention solves the problem that the electric field is difficult to penetrate thick piles by laying multiple wells inside the landfill and drilling these wells deep into the landfill and the impermeable layer. The layout of the well arrangement is optimized to improve the detection range and accuracy; different from the traditional surface electrical measurement method, the present invention uses coupled electric field technology, that is, applying an electric field at the bottom of the landfill and the surrounding rock outside the pile through drilling, enhancing the electrical signal in the leakage area, and then measuring the voltage distribution and vertical electric field components through the coupled electric field in the well, and further analyzing the changes in voltage and vertical electric field components. This method design ensures the effective conduction of the electric field method in thick piles, improves the depth and accuracy of detection, and at the same time, the laying of DC power supply can perform real-time electric field measurement of the landfill, which can detect leakage problems at an early stage and reduce the risk of environmental pollution.

[0036] In an experimental embodiment of the present invention, Figure 3 As shown, the embodiment of the present invention uses this model as an example to conduct a simulation experiment analysis on the leakage of a thick landfill. First, a landfill model is established and leakage points are set. Exhaust holes or drill holes are set at different positions away from the leakage points. After a DC electric field is applied to the top of the landfill, the distribution of the coupled electric field at different depths and regions is analyzed. Figure 4The simulation results shown are the changes of potential with depth in different wells. Analysis shows that when the potential value is far away from the leakage point, the change of potential value with depth is relatively stable; when it is close to the leakage point, the potential value drops significantly; Figure 5 The simulation results shown are the changes of the Z-direction electric field component with depth in different wells. Analysis shows that the closer to the leakage point, the more drastic the change of the Z-direction electric field component with depth. The model reflects the difference in electric field distribution at different distances from the leakage point, especially near the leakage point. The electric field distribution shows a significant change characteristic. This change trend provides an important basis for identifying the leakage location.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A well-coupled electric field precise positioning technology for thick landfill leakage, characterized in that: include: Setting a plurality of well positions in the landfill for drilling to obtain a plurality of drilled wells; A DC electric field was applied to the top of the landfill and the voltage was measured at each borehole; Establish a distribution curve according to the voltage of each well, and obtain a set number of minimum value points in the distribution curve in order from small to large; According to the drilling fitting polygons corresponding to the set number of minimum value points, the centroid of the fitting polygon is obtained to obtain the leakage point of the landfill.

2. The well coupled electric field precise positioning technology for thick landfill leakage according to claim 1 is characterized by: The drilling depth exceeds the garbage dump and reaches the impermeable layer, but does not exceed the impermeable layer.

3. The well coupling electric field precise positioning technology for thick landfill leakage according to claim 1 is characterized by: The direct current electric field is applied to the top and bottom of the landfill, specifically, a plurality of electrodes are evenly arranged on the top of the landfill to provide a positive voltage, and the bottom of the landfill is grounded.

4. The well coupled electric field precise positioning technology for thick landfill leakage according to claim 1 is characterized by: The wellbore is also provided with measuring electrodes and an electric field measuring device for measuring the voltage and vertical electric field component corresponding to each wellbore.

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