Comprehensive measuring device for hydraulic parameters and various electric responses

Abstract

The utility model relates to the technical field of rare earth resource exploration, in particular to a comprehensive measuring device for hydraulic parameters and various electric responses, which comprises a constant-pressure water supply component, an adjusting valve, a measuring soil column container, a collecting and measuring component, a pressure sensor, a recorder and an electric response measuring instrument. The soil column measuring container comprises a container main body, a microporous baffle plate, two current electrodes and two measuring electrodes, the water inlet end and the water outlet end of the constant-pressure water supply assembly are respectively communicated with the container main body through pipelines, and the storage and collection assembly is arranged on the pipeline between the water outlet and the constant-pressure water supply assembly; a sample cavity between the two microporous baffles in the container main body is used for filling a sample; the adjusting valve is used for adjusting the flow; the pressure sensor, the collecting and measuring assembly, the measuring electrode and the current electrode are used for measuring hydraulic parameters and flowing electric response. According to the utility model, the hydraulic parameters and various electric responses of the sample can be accurately measured, and the electric responses under different hydraulic conditions can be measured.

Description

Technical Field

[0001] This utility model relates to the field of rare earth resource exploration technology, and in particular to a comprehensive measuring device for hydraulic parameters and multiple electrical responses. Background Technology

[0002] In geomorphic-hydrological environments with intense soil water seepage, rare earth elements (REEs) in protoliths (granite, volcanic rocks, etc.) undergo long-term weathering, transforming from the mineral phase to the ionic phase and becoming adsorbed and enriched in clay minerals, forming ion-adsorbed REE deposits. Layered clay minerals, possessing adsorption sites and carrying a negative surface charge, attract REE cations to form an electrical double layer when immersed in an electrolyte. The induced polarization effect reflects both the conductivity and polarization characteristics of the underground medium through the amplitude and phase of the signal in the frequency domain. The clay mineral content and ion concentration in the pore solution affect the charge distribution in the solution and the electrical double layer structure, thus altering the conductivity and polarization of the medium. Furthermore, when the electrolyte solution flows through a porous medium under external force, ions move along with it in the electrical double layer at the mineral-fluid interface, forming a flowing current. Positive and negative ions accumulate at both ends of the particles, creating a potential difference, i.e., the flow potential. The absolute value of the flow potential is linearly correlated with the external force; the ratio is called the flow potential coefficient. Therefore, for the exploration and monitoring requirements of ion adsorption type rare earth deposits, theoretically, combining the two electrical exploration methods can provide rich electrical parameters and multi-parameter comparative interpretations.

[0003] By simulating the hydrogeological environment of ion-adsorption rare earth deposits indoors, collecting geophysical data from solutions with different ion concentrations, sand samples, and hydraulic gradients, and analyzing these data, this preliminary engineering work for the application of new field technologies can improve field work efficiency, reduce exploration costs, and help understand the relationship between microscopic electrochemical mechanisms and macroscopic geophysical responses. This provides valuable reference for understanding the mineralization mechanism and enrichment theory of ion-adsorption rare earth deposits, as well as for applying related geophysical technologies to rare earth resource exploration.

[0004] Existing experimental setups require complex pretreatment processes for measuring flow potential during hydraulic and electrical response measurements, which can affect the physicochemical properties of the samples. Therefore, equipment needs to be developed specifically for the characteristics of the samples. When using existing electrical response and hydraulic parameter measurement devices to measure the hydraulic parameters and electrical response of the same sample, the sample needs to be transferred between the two devices. Each time the sample is moved to the next measurement device, a sand sample is used to compact and fill the soil column container. Each compaction alters the internal micro-geometry of the soil sample, affecting the measurement results and hindering the exploration of the relationship between microscopic hydrological factors and macroscopic electrical response.

[0005] Therefore, it is necessary to provide a new integrated measurement device for hydraulic parameters and multiple electrical responses to solve the above-mentioned technical problems. Utility Model Content

[0006] The main objective of this invention is to provide a comprehensive measuring device for hydraulic parameters and multiple electrical responses, thereby addressing the problem that the microstructure of soil samples changes when existing measuring devices measure multiple electrical responses and hydraulic parameters under different water quality conditions.

[0007] To achieve the above objectives, this utility model proposes a comprehensive measuring device for hydraulic parameters and multiple electrical responses, including a constant pressure water supply component, a regulating valve, a measuring soil column container, a pressure sensor, a collection and measurement component, a recorder, and an electrical response measuring instrument;

[0008] The soil column measuring container includes a container body, microporous baffles, two measuring electrodes, and two current electrodes. A cavity is formed within the container body. An outlet and an inlet, communicating with the cavity, are respectively located at the upper and lower ends of the container body. The outlet is connected to the inlet of the collecting and measuring component via a pipe, and the inlet is connected to the outlet of the constant pressure water supply component via a pipe. Two microporous baffles are arranged vertically at intervals within the cavity, dividing it into an upper cavity, a sample cavity, and a lower cavity arranged sequentially from top to bottom. The upper cavity communicates with the outlet, and the lower cavity communicates with the inlet. The sample cavity is used to fill the sample.

[0009] Two measuring electrodes are vertically spaced on the container body, with one end of each measuring electrode extending into the sample. The measuring electrodes can be electrically connected to the measuring end of the electrical response measuring instrument or the recorder. Two current electrodes are respectively located in the upper cavity and the lower cavity, and are symmetrically arranged about the two measuring electrodes. The current electrodes are used to connect to the power supply end of the electrical response measuring instrument.

[0010] The regulating valve is installed on the pipeline between the water inlet and the constant pressure water supply component; the pressure sensor is detachably installed on the container body, and the pressure sensor is used to measure the pore water pressure of the sample; the collection and measurement component is installed on the pipeline between the water outlet and the constant pressure water supply component.

[0011] Optionally, the container body includes a cylindrical body, a cap, a first inlet unit, a second inlet unit, and a filter screen, wherein the cavity is formed inside the cylindrical body, and the cap is threadedly connected to the open end of the cylindrical body;

[0012] The first socket unit includes two first socket structures spaced apart in a vertical direction. The first socket structures are connected to the sample chamber, and the two measuring electrodes are respectively disposed in the two first socket structures.

[0013] The second socket unit includes two second socket structures spaced apart in a vertical direction. The second socket structures are connected to the sample chamber, and each of the second socket structures is equipped with the pressure sensor. The two second socket structures are respectively arranged in a one-to-one correspondence with the two first socket structures, and the pressure sensor in the second socket structure is at the same height as the corresponding first socket structure.

[0014] Optionally, the first insertion structure includes a first tubular body and a sealing plug. The first tubular body is in communication with the sample chamber, and the sealing plug is connected to the end of the first tubular body away from the cylinder. The sealing plug has a first through hole for interference fit of the measuring electrode.

[0015] Optionally, the second socket structure includes a second tubular body and a sealing sleeve. The second tubular body includes a horizontal section and a vertical section that are connected to each other, and the horizontal section is connected to the sample chamber. The pressure sensor is disposed in the horizontal section. The sealing sleeve seals the end of the vertical section away from the horizontal section, and the sealing sleeve has a second through hole for the pressure sensor wire to be interference-fitted.

[0016] Optionally, the second insertion structure includes a second tubular body and a plug. The second tubular body includes a horizontal section and a vertical section that are connected to each other. The horizontal section is connected to the sample chamber. The pressure sensor is disposed in the horizontal section. The plug is connected to the end of the vertical section away from the horizontal section.

[0017] Optionally, the height of the measuring soil column container is 15cm-21cm; the distance between the two first insertion structures is 5cm-7cm.

[0018] Optionally, the sample chamber is provided with two limiting plates that correspond one-to-one with the microporous baffles. The microporous baffles are located on the side of the limiting plates facing the sample chamber, and the filter screen is provided on the side of the microporous baffles facing the sample chamber.

[0019] Optionally, the collection and measurement component further includes a flow meter, a water quality analyzer, and a feed bottle. The flow meter is installed in the pipeline between the outlet and the constant pressure water supply component. The feed bottle is installed in the pipeline between the outlet and the inlet of the constant pressure water supply component. The water quality analyzer is used to detect the water quality parameters in the feed bottle.

[0020] Optionally, the collection and measurement assembly further includes a collection tube and a solution collection device, wherein the collection tube is connected to the feed bottle, and the solution collection device collects the sample solution through the collection tube.

[0021] Optionally, the constant pressure water supply assembly includes a constant pressure water tank, a water storage tank, and a water pump. The constant pressure water tank includes an outer measuring cylinder and an inner measuring cylinder. The outer measuring cylinder is positioned above the measuring soil column container, and its bottom is connected to the water storage tank via a pipeline. The inner measuring cylinder is positioned inside the outer measuring cylinder, and it is connected to both the water storage tank and the water inlet via pipelines. The water pump is positioned on the pipeline between the inner measuring cylinder and the water storage tank.

[0022] In this utility model, the sample is loaded into the sample chamber. The constant pressure water supply component can deliver the solution into the soil column container through the inlet and can also recover the solution flowing out of the soil column container, thereby realizing the circulation of the solution. When measuring hydraulic parameters, the measuring electrode and pressure sensor are connected to the recorder so that the recorder can record the potential difference and pore water pressure between the two measuring electrodes. By collecting the data, the hydraulic parameters of the solution in the pipeline between the outlet and the constant pressure water supply component can be measured. When measuring the electrical response, the measuring electrode and current electrode are electrically connected to the measuring end and power supply end of the electrical response measuring instrument, respectively, to measure the complex conductivity of the sample between the two measuring electrodes. This invention can accurately measure the hydraulic parameters and various electrical responses of samples. The solution flow rate can be controlled by adjusting the valve to facilitate the measurement of electrical responses under different hydraulic conditions. This reduces the impact on the microstructure of the sample during transfer between different devices, ensuring the stability of the measurement results. It can also monitor the water quality conditions of saturated soil samples simultaneously by collecting the measurement components. This invention has certain reference value for rare earth resource exploration and helps to explore the relationship between water quality conditions, hydraulic conditions and various electrical responses. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of the integrated measuring device for hydraulic parameters and multiple electrical responses in this embodiment of the present invention when measuring the electrical response;

[0025] Figure 2 This is a cross-sectional view of the integrated measuring device for hydraulic parameters and various electrical responses in an embodiment of this utility model;

[0026] Figure 3 for Figure 2 Sectional view II;

[0027] Figure 4This is a partial structural diagram of the integrated measuring device for hydraulic parameters and multiple electrical responses in this embodiment of the present invention when measuring hydraulic parameters.

[0028] Explanation of icon numbers:

[0029] 1. Constant pressure water supply assembly; 1.1. Constant pressure water tank; 1.1.1. Outer measuring cylinder; 1.1.2. Inner measuring cylinder; 1.2. Water storage tank; 1.3. Water pump; 2. Measuring soil column container; 2.1. Container body; 2.1.1. Upper cavity; 2.1.2. Sample cavity; 2.1.3. Lower cavity; 2.1.4. Cylinder; 2.1.5. Cap; 2.1.6. First insertion structure; 2.1.7. Second insertion structure; 2. 1.8 Filter screen; 2.1.9 Outlet; 2.1.10 Inlet; 2.2 Microporous baffle; 2.3 Measuring electrode; 2.4 Current electrode; 2.5 Limiting plate; 3 Regulating valve; 4 Pressure sensor; 5 Flow meter; 6 Recorder; 7 Electrical response measuring instrument; 7.1 Power supply terminal; 7.2 Measuring terminal; 8 Water quality analyzer; 9 Feed bottle; 10 Collection tube; 11 Solution collection device.

[0030] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0031] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered by the claims.

[0032] This invention proposes a comprehensive measuring device for hydraulic parameters and multiple electrical responses, aiming to solve the problem that the micro-geometry of soil samples changes when existing measuring devices measure multiple electrical responses and hydraulic parameters of soil samples under different water quality conditions.

[0033] Example 1

[0034] like Figures 1 to 4As shown, a comprehensive measuring device for hydraulic parameters and multiple electrical responses is disclosed. The device includes a constant pressure water supply assembly 1, a soil column measuring container 2, a regulating valve 3, a pressure sensor 4, a collection and measurement assembly, a recorder 6, and an electrical response measuring instrument 7. The soil column measuring container 2 includes a container body 2.1, a microporous baffle 2.2, two measuring electrodes 2.3, and two current electrodes 2.4. A cavity is formed inside the container body 2.1. The lower two ends are respectively provided with an outlet 2.1.9 and an inlet 2.1.10 communicating with the cavity. The outlet 2.1.9 is connected to the inlet of the constant pressure water supply component 1 through a pipeline, and the inlet 2.1.10 is connected to the outlet of the constant pressure water supply component 1 through a pipeline. The cavity is provided with two microporous baffles 2.2 arranged vertically at intervals. The two microporous baffles 2.2 divide the cavity into an upper cavity 2.1.1, a sample cavity 2.1.2 and a lower cavity 2.1 arranged from top to bottom. 3. The upper chamber 2.1.1 is connected to the outlet 2.1.9, and the lower chamber 2.1.3 is connected to the inlet 2.1.10. The sample chamber 2.1.2 is used to fill the sample. Two measuring electrodes 2.3 are vertically spaced on the container body 2.1, and one end of the measuring electrode 2.3 extends into the sample. The measuring electrode 2.3 can be electrically connected to the measuring end 7.2 of the electrical response measuring instrument 7 or the recorder 6. Two current electrodes 2.4 are respectively located in the upper chamber 2.1.1 and the lower chamber 2. 1.3, and two current electrodes 2.4 are symmetrically arranged about the two measuring electrodes 2.3. The current electrodes 2.4 are used to connect to the power supply terminal 7.1 of the electrical response measuring instrument 7; the regulating valve 3 is set on the pipeline between the water inlet 2.1.10 and the constant pressure water supply component 1; the pressure sensor 4 is detachably set on the container body 2.1. The pressure sensor 4 is used to measure the pore water pressure of the sample; the flow meter 5 is set on the pipeline between the water outlet 2.1.9 and the constant pressure water supply component 1.

[0035] In actual operation, the sample is filled into the sample chamber 2.1.2. The constant pressure water supply component 1 can deliver the solution into the soil column container 2 through the inlet 2.1.10 and can also recover the solution flowing out of the outlet 2.1.9 of the soil column container 2, thereby realizing the circulation of the solution. When measuring hydraulic parameters, the measuring electrode 2.3 and the pressure sensor 4 are electrically connected to the recorder 6, so that the recorder 6 can record the potential difference and pore water pressure between the two measuring electrodes 2.3. By collecting the measurement components, the hydraulic parameters of the solution in the pipeline between the outlet 2.1.9 and the constant pressure water supply component 1 can be measured. When measuring the electrical response, the measuring electrode 2.3 and the current electrode 2.4 are electrically connected to the measuring end 7.2 and the power supply end 7.1 of the electrical response measuring instrument 7, respectively. The current electrode 2.4 is set in the upper chamber 2.1.1 and the lower chamber 2.1.3 to energize the solution in the cavity, thereby measuring the complex conductivity of the sample between the two measuring electrodes 2.3. This embodiment can measure the hydraulic parameters and various electrical responses of the sample. The solution flow rate can be controlled by adjusting valve 3 to facilitate the measurement of electrical responses under different hydraulic conditions. This reduces the impact on the microstructure of the sample during transfer between different devices, ensuring the stability of the measurement results. It can also monitor the water quality conditions of saturated soil samples simultaneously by collecting the measurement components. This embodiment can also replace the sample to change the sandy soil conditions, which helps to explore the relationship between water quality conditions, hydraulic conditions and various electrical responses. Different hydraulic conditions, different water quality conditions and different sandy soil conditions have certain reference value for the exploration of rare earth resources. Preferably, the pipeline is a flexible tube, the measuring electrode 2.3 is an Ag / AgCl electrode, the current electrode 2.4 is a copper electrode, the electrical response measuring instrument 7 is a full-waveform impedance analyzer, the pressure sensor 4 is a miniature dynamic pressure sensing probe, and the recorder 6 is a paperless recorder 6; the measuring electrode 2.3 and the current electrode 2.4 together form a four-electrode device connected to the full-waveform impedance analyzer to measure the complex resistivity of the sample; in the absence of power supply, the measuring electrode 2.3 and the miniature dynamic pressure sensing probe are embedded in the side wall and simultaneously connected to the paperless recorder 6 to record the time-series data of the pore water pressure value and potential difference at two locations.

[0036] Specifically, the container body 2.1 includes a cylindrical body 2.1.4, a cap 2.1.5, a first insertion unit, a second insertion unit, and a filter screen 2.1.8. A cavity is formed inside the cylindrical body 2.1.4, and the cap 2.1.5 is threadedly connected to the open end of the cylindrical body 2.1.4. The first insertion unit includes two first insertion structures 2.1.6 spaced apart in the vertical direction. The first insertion structures 2.1.6 communicate with the sample chamber 2.1.2, and two measuring electrodes 2.3 are respectively disposed in the two first insertion structures. In section 2.1.6, the second insertion unit includes two second insertion structures 2.1.7 arranged vertically at intervals. The second insertion structures 2.1.7 are connected to the sample chamber 2.1.2, and each second insertion structure 2.1.7 is equipped with a pressure sensor 4. The two second insertion structures 2.1.7 are respectively arranged in a one-to-one correspondence with the two first insertion structures 2.1.6, and the pressure sensor 4 in the second insertion structure 2.1.7 is at the same height as the corresponding first insertion structure 2.1.6. The cap 2.1.5 is threadedly connected to the cylinder 2.1.4 to facilitate sample loading into the sample chamber 2.1.2. A first insertion structure 2.1.6 and a second insertion structure 2.1.7 are provided to facilitate the placement of the measuring electrode 2.3 and the pressure sensor 4. When measuring complex resistivity, the pressure sensor 4 in the second insertion structure 2.1.7 can be removed to reduce interference factors in complex resistivity measurement, ensure the accuracy of the measurement results, and protect the sensor probe. The filter 2.1.8 effectively secures the sample in the sample chamber 2.1.2 while ensuring the normal passage of solution. Preferably, the cylinder 2.1.4 is made of plexiglass, and the filter 2.1.8 is a nylon filter.

[0037] The first insertion structure 2.1.6 includes a first tubular body and a sealing plug. The first tubular body communicates with the sample chamber 2.1.2, and the sealing plug seals the end of the first tubular body away from the cylinder 2.1.4. The sealing plug has a first through hole for the measuring electrode 2.3 to be interference-fitted. The measuring electrode 2.3 penetrates the first insertion structure 2.1.6 and is inserted into the sample in the sample chamber 2.1.2. The combination of the first tubular body and the sealing plug facilitates the replacement of the measuring electrode 2.3, preventing damage to the electrode from prolonged use and ensuring the accuracy of the device. In this embodiment, the sealing plug is a rubber plug used to seal the first tubular body, and the measuring electrode is interference-fitted with the first through hole on the sealing plug to seal the gap between the measuring electrode and the sealing plug, thus preventing solution leakage.

[0038] Furthermore, the second insertion structure 2.1.7 includes a second tubular body and a sealing sleeve. The second tubular body includes a horizontal section and a vertical section that are connected, and the horizontal section is connected to the sample chamber 2.1.2. The pressure sensor 4 is disposed in the horizontal section. The sealing sleeve seals the end of the vertical section away from the horizontal section, and the sealing sleeve has a second through hole for the pressure sensor 4 wire to be press-fitted. The second tubular body, composed of the horizontal and vertical sections, can prevent solution leakage when the pressure sensor 4 is removed or placed. In this embodiment, the sealing sleeve is a variable diameter rubber sleeve. The wall of the vertical section of the second tubular body is press-fitted with the large diameter end of the variable diameter rubber sleeve, and the wire of the pressure sensor 4 passes through the sealing sleeve and is press-fitted with the small diameter end of the variable diameter rubber sleeve. This can effectively seal the second tubular body and also seal the gap between the pressure sensor 4 wire and the sealing sleeve, preventing solution leakage.

[0039] In this embodiment, the height of the soil column container 2 is measured to be 15cm-21cm; the distance between the two first insertion structures 2.1.6 is 5cm-7cm. These dimensions meet the practical requirements of electrical resistivity tomography (EDT) technology, ensuring accurate measurement.

[0040] Furthermore, the sample chamber 2.1.2 is equipped with two limiting plates 2.5, each corresponding to a microporous baffle 2.2. The microporous baffle 2.2 is positioned on the side of the limiting plate 2.5 facing the sample chamber 2.1.2, and a filter screen 2.1.8 is provided on the side of the microporous baffle 2.2 facing the sample chamber 2.1.2. The limiting plate 2.5 effectively limits the microporous baffle 2.2, and the cooperation between the microporous baffle 2.2 and the filter screen 2.1.8 effectively prevents sand particles in the sample from moving with the fluid or clogging the inlet / outlet 2.1.9. Preferably, the mesh size of the filter screen 2.1.8 is larger than the mesh size of the sand particles in the sample.

[0041] In this embodiment, the collection and measurement components also include a flow meter 5, a water quality analyzer 8, and a feed bottle 9. The flow meter 5 is installed in the pipeline between the outlet 2.1.9 and the constant pressure water supply component 1; the feed bottle 9 is installed in the pipeline between the outlet 2.1.9 and the inlet of the constant pressure water supply component 1; and the water quality analyzer 8 is used to detect the water quality parameters in the feed bottle 9. The flow meter 5 at the outlet 2.1.9 can display the flow rate. In this embodiment, the water quality analyzer 8 is calibrated with a standard solution.

[0042] In this embodiment, the measurement assembly further includes a sampling tube 10 and a solution collection device 11. The sampling tube 10 is connected to the feed bottle 9, and the solution collection device 11 collects the sample solution through the sampling tube 10. The solution collection device 11 samples the solution through the sampling tube 10 to facilitate chemical analysis.

[0043] In addition, the constant pressure water supply component 1 includes a constant pressure water tank 1.1, a water storage tank 1.2, and a water pump 1.3. The constant pressure water tank 1.1 includes an outer measuring cylinder 1.1.1 and an inner measuring cylinder 1.1.2. The outer measuring cylinder 1.1.1 is set above the measuring soil column container 2, and the bottom of the outer measuring cylinder 1.1.1 is connected to the water storage tank 1.2 through a pipeline. The inner measuring cylinder 1.1.2 is set inside the outer measuring cylinder 1.1.1, and the inner measuring cylinder 1.1.2 is connected to the water storage tank 1.2 and the water inlet 2.1.10 through pipelines. The water pump 1.3 is set on the pipeline between the inner measuring cylinder 1.1.2 and the water storage tank 1.2. The inner measuring cylinder 1.1.2 is equipped with volume graduations, and the solution overflowing from the inner measuring cylinder 1.1.2 into the outer measuring cylinder 1.1.1 can flow back to the water storage tank 1.2 by gravity. The water pump 1.3 pumps the solution from the water storage tank 1.2 into the inner measuring cylinder 1.1.2. The solution in the inner measuring cylinder 1.1.2 then flows into the soil column container 2 through the inlet 2.1.10 by gravity, and then flows back to the water storage tank 1.2 from the top outlet 2.1.9 via the flow meter 5 and the water quality analyzer 8, thus achieving solution circulation. In this embodiment, the water pump 1.3 is a magnetic pump to prevent solution contamination.

[0044] Example 2

[0045] The difference from Embodiment 1 is that the second insertion structure 2.1.7 includes a second tubular body and a plug. The second tubular body includes a horizontal section and a vertical section that are connected. The horizontal section is connected to the sample chamber 2.1.2. The pressure sensor 4 is located in the horizontal section, and the plug is connected to the end of the vertical section away from the horizontal section. When measuring the flow potential response, the pressure sensor is used to measure the head difference between the two measuring electrodes, and the recorder measures the potential difference between the two measuring electrodes, thereby calculating the flow potential coupling coefficient. When measuring the complex resistivity, power needs to be supplied to the soil column container. To avoid interference from the pressure sensor 4 in the measurement of complex resistivity, the pressure sensor 4 needs to be removed from the container body 2.1, and the sealing sleeve is replaced with a plug to achieve complete sealing of the second tubular body. In this embodiment, the plug is a rubber sleeve without a second through hole, and the plug's opening is pressurized to ensure that the plug can fit tightly to the opening.

[0046] Hydraulic parameters include head difference and flow rate; electrical response includes potential difference and complex conductivity. The specific measurement steps are as follows:

[0047] Sample and solution filling: After fixing the lower microporous baffle 2.2, lay a layer of nylon filter screen 2.1.8 slightly larger than the mesh size of the sand. Slowly add sand to fill the sample chamber 2.1.2. During the sand filling process, continuously tamp the soil sample with a clean wooden stick. When the specified height is reached, insert the measuring electrode 2.3 with a perforated rubber plug and connect the pressure sensor 4 to the tube opening with a variable diameter rubber sleeve to ensure no leakage. Finally, tighten the top cap. Pour the prepared electrolyte solution into the water storage tank 1.2.

[0048] Establishing the circulation process: The magnetic pump pumps the solution from the storage tank 1.2 into the constant water level storage tank 1.2 until a constant water head is reached, with excess water returning to the storage tank 1.2; after reaching the constant water head, the regulating valve 3 is opened to begin saturation, initially maintaining a slow flow rate to allow the water level in the soil to rise slowly; during the saturation process, the water level is constantly monitored to ensure that no gas remains in the container and there is no leakage; the solution flows through the feed bottle 9 and finally returns to the storage tank 1.2 to form a circulation, and finally, a check is performed to ensure that there are no air bubbles in the hose;

[0049] Sample measurement: During the static water time (i.e., when the flow rate is 0), the initial potential difference and pressure value are recorded. The flow rate is controlled by adjusting valve 3, which gradually increases the flow rate in four different constant-rate stages. The flow rate is kept constant for no more than 10 minutes in each stage. The paperless recorder 6 simultaneously records the potential difference and pore water pressure, and also records the flow rate measured by flow meter 5. After the four stages are completed, the valve and pump are closed to ensure that the flow rate is 0, so that the sample returns to a static state and the data is collected.

[0050] The time-series data was plotted as the pressure values ​​at two points changing over time, divided into different stages: static, flow velocity 1, flow velocity 2, flow velocity 3, flow velocity 4, and static again. After removing abrupt and outlier values ​​at each stage, the average and standard deviation of the head difference were calculated. The flow rate at each stage was recorded three times, and the average and standard deviation were calculated. The saturated hydraulic conductivity coefficient was calculated by linearly fitting the average flow rate as a function of the pressure difference: K = Q·L / Δh·A.

[0051] In the formula, K represents the saturated hydraulic conductivity coefficient of the saturated sand sample in the electrolyte solution; Q represents the average flow rate measured at different stages; Δh represents the head difference measured by the two pressure sensors 4 at the two locations; L represents the seepage length; and A represents the cross-sectional area of ​​the water flow.

[0052] The time-series data were plotted as the changes in pressure and potential difference at two points over time, divided into different stages: static, flow velocity 1, flow velocity 2, flow velocity 3, flow velocity 4, and static. After removing some abrupt and outlier values ​​in each stage, the average value and standard deviation of the pressure difference (ΔP) and potential difference (ΔE) were calculated. To eliminate the influence of temperature changes or electrode ion diffusion on the non-polarized electrode, a four-step correction process was performed: 1) The potential difference curve was shifted so that the potential difference in the initial static stage was 0; 2) The remaining potential difference at the end of the static stage was determined as Vr; 3) The remaining potential difference was assumed to change linearly with time; 4) Finally, the time-dependent remaining potential difference was subtracted from the shifted potential difference, and the average potential difference after linear fitting correction was used to calculate the flow potential coupling coefficient: C = ΔE / ΔP.

[0053] In the formula, C represents the flow potential coupling coefficient of the saturated sand sample in the electrolyte solution; ΔE represents the average potential difference after correction at different stages of the measuring electrode 2.3; and ΔP represents the pressure difference measured by the two position pressure sensors 4.

[0054] When measuring complex resistivity, during the static water time (i.e., when the flow rate is 0), a four-electrode device is used to connect to a full-waveform impedance meter. Current is injected into the container through current electrode 2.4. Specifically, two measuring electrodes 2.3 and two current electrodes 2.4 together form a symmetrical four-electrode device. Alligator clips are used to hold the four electrodes. Current electrode 2.4 is used as the AB terminal to supply AC power, and measuring electrode 2.3 is used as the MN terminal to connect to the full-waveform impedance meter to measure the amplitude and phase of the sample's saturated complex resistivity under static water conditions.

[0055] The reciprocal of the amplitude of the complex resistivity is the amplitude of the complex conductivity. The amplitude and absolute value of the complex conductivity amplitude and phase are plotted as a function of the frequency signal. The amplitude and phase of the complex conductivity obtained from the measurement of saturated quartz sand are converted into the real and imaginary parts of the complex conductivity. The formation factor F is calculated using formula (1).

[0056]

[0057] In the formula, α for unconsolidated sand is taken as 0.1, and σ w The conductivity is measured by a water quality analyzer, and σ' is the angular frequency ω = 1s. -1 The real part of the time-complex conductivity, σ" is the angular frequency ω = 1s -1 Imaginary part of time-complex conductivity.

[0058] Compared with existing experimental equipment and devices, the integrated measurement device for hydraulic parameters and multiple electrical responses in this embodiment has the following advantages:

[0059] 1. Compared with the traditional pump-driven measurement of flow potential, using a constant water level system to control the flow rate under gravity is beneficial to obtain a more stable flow rate, preventing the flow of liquid from having a significant impact on the physical structure of the sample under test. This maintains relatively stable pore water pressure and potential difference data under constant flow rate conditions, with smaller fluctuations. Gravity-driven soil seepage can more realistically simulate the soil water seepage process in the weathering crust and reflect the characteristics of soil samples with ion adsorption.

[0060] 2. Maintaining the fluid flow direction from bottom to top in the soil column container can achieve a better saturation state. The higher the degree of saturation of the soil sample, the smaller the error of the experimental measurement results.

[0061] 3. The device can simultaneously perform measurements of different properties, including mechanical, electrical, and chemical properties. In addition to effectively measuring the electrical and mechanical characteristics of saturated porous media, the device can maintain solution circulation and achieve a certain dynamic equilibrium. Firstly, recycling reduces reagent waste. Secondly, it can promptly sample and analyze the seepage solution after measuring hydraulic and electrical properties, which is beneficial for obtaining dynamic hydrological data and realizing dynamic monitoring of the process.

[0062] 4. The device has a simple, modular, and expandable structure. The flow circulation system has a simple structure, all components are readily available, the system is easy to build and expand, and the components can be disassembled and washed, facilitating assembly, replacement, and cleaning, thus avoiding cross-contamination of samples.

[0063] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A device for the integrated measurement of hydraulic parameters and a plurality of electrical responses, characterized in that, The constant pressure water supply assembly (1), the measuring soil column container (2), the adjusting valve (3), the pressure sensor (4), the collection measuring assembly, the recorder (6) and the electric response measuring instrument (7) are included. The measuring soil column container (2) includes a container body (2.1), a microporous baffle (2.2), two measuring electrodes (2.3) and two current electrodes (2.4), a cavity is formed in the container body (2.1), and water outlets (2.1.9) and water inlets (2.1.10) are formed in the upper and lower ends of the container body (2.1) and communicate with the cavity; the water outlets (2.1.9) are connected with the water inlet end of the constant pressure water supply assembly (1) through pipelines, the water inlets (2.1.10) are connected with the water outlet end of the constant pressure water supply assembly (1) through pipelines; two microporous baffles (2.2) are arranged in the cavity in a vertical direction, and the cavity is divided into an upper cavity (2.1.1), a sample cavity (2.1.2) and a lower cavity (2.1.3) arranged in sequence from top to bottom; the upper cavity (2.1.1) communicates with the water outlet (2.1.9), the lower cavity (2.1.3) communicates with the water inlet (2.1.10), and the sample cavity (2.1.2) is used for loading samples; The two measuring electrodes (2.3) are arranged on the container body (2.1) in a vertical direction, and one end of the measuring electrode (2.3) extends into the sample; the measuring electrode (2.3) can be electrically connected with the measuring end (7.2) of the electric response measuring instrument (7) or the recorder (6); two current electrodes (2.4) are arranged in the upper cavity (2.1.1) and the lower cavity (2.1.3), and the two current electrodes (2.4) are symmetrically arranged about the two measuring electrodes (2.3); the current electrode (2.4) is used for connecting the power supply end (7.1) of the electric response measuring instrument (7); The adjusting valve (3) is arranged on the pipeline between the water inlet (2.1.10) and the constant pressure water supply assembly (1); The pressure sensor (4) is detachably arranged on the container body (2.1), and is used for measuring the pore water pressure of the sample; and the collection measuring assembly is arranged on the pipeline between the water outlet (2.1.9) and the constant pressure water supply assembly (1).

2. The apparatus of claim 1, wherein The container body (2.1) includes a barrel (2.1.4), a cap (2.1.5), a first socket unit, a second socket unit and a filter screen (2.1.8); the barrel (2.1.4) forms the cavity; and the cap (2.1.5) is threadedly connected with the opening end of the barrel (2.1.4); The first socket unit includes two first socket structures (2.1.6) arranged in a vertical direction, the first socket structure (2.1.6) communicates with the sample cavity (2.1.2), and the two measuring electrodes (2.3) are arranged in the two first socket structures (2.1.6); The second socket unit comprises two second socket structures (2.1.7) arranged in a vertical direction, the second socket structures (2.1.7) are in communication with the sample cavity (2.1.2), and the pressure sensor (4) is arranged in the second socket structure (2.1.7); the two second socket structures (2.1.7) are arranged one by one with the two first socket structures (2.1.6), and the pressure sensor (4) in the second socket structure (2.1.7) has the same arrangement height as the corresponding first socket structure (2.1.6).

3. The integrated measuring device for hydraulic parameters and multiple electrical responses as described in claim 2, characterized in that, The first socket structure (2.1.6) comprises a first tubular body and a sealing plug, the first tubular body is in communication with the sample cavity (2.1.2), and the sealing plug is arranged at one end of the first tubular body away from the barrel (2.1.4), and the sealing plug is provided with a first through hole for the interference arrangement of the measuring electrode (2.3).

4. The integrated measuring device for hydraulic parameters and multiple electrical responses as described in claim 3, characterized in that, The second socket structure (2.1.7) comprises a second tubular body and a sealing sleeve, the second tubular body comprises a horizontal segment and a vertical segment in communication, the horizontal segment is in communication with the sample cavity (2.1.2), and the pressure sensor (4) is arranged in the horizontal segment; the sealing sleeve is arranged at one end of the vertical segment away from the horizontal segment, and the sealing sleeve is provided with a second through hole for the interference arrangement of the lead wire of the pressure sensor (4).

5. The integrated measuring device for hydraulic parameters and multiple electrical responses as described in claim 3, characterized in that, The second socket structure (2.1.7) comprises a second tubular body and a sealing sleeve, the second tubular body comprises a horizontal segment and a vertical segment in communication, the horizontal segment is in communication with the sample cavity (2.1.2), and the pressure sensor (4) is arranged in the horizontal segment; the sealing sleeve is arranged at one end of the vertical segment away from the horizontal segment, and the sealing sleeve is provided with a second through hole for the interference arrangement of the lead wire of the pressure sensor (4).

6. The apparatus of any one of claims 2 to 5, wherein, The height of the measuring soil column container (2) is 15cm-21cm; the distance between the two first socket structures (2.1.6) is 5cm-7cm.

7. The apparatus of any one of claims 2 to 5, wherein the plurality of electrical responses are selected from the group consisting of: impedance, capacitance, conductance, resistance, inductance, and combinations thereof. The sample cavity (2.1.2) is provided with two limiting plates (2.5) arranged one by one with the microporous baffle (2.2), the microporous baffle (2.2) is arranged on the side of the limiting plate (2.5) facing the sample cavity (2.1.2), and the side of the microporous baffle (2.2) facing the sample cavity (2.1.2) is provided with the filter screen (2.1.8).

8. The apparatus of any one of claims 2 to 5, wherein, The collection and measurement assembly further comprises a flow meter (5), a water quality detector (8) and a feeding bottle (9), the flow meter (5) is arranged on the pipeline between the water outlet (2.1.9) and the constant pressure water supply assembly (1); the feeding bottle (9) is arranged on the pipeline between the water outlet (2.1.9) and the water inlet end of the constant pressure water supply assembly (1), and the water quality detector (8) is used for detecting the water quality parameter in the feeding bottle (9).

9. The integrated measuring device for hydraulic parameters and multiple electrical responses as described in claim 8, characterized in that, The collection and measurement assembly further comprises a collection pipe (10) and a solution collection device (11), the collection pipe (10) is in communication with the feeding bottle (9), and the solution collection device (11) collects sample solution through the collection pipe (10).

10. The apparatus of any one of claims 1 to 5, wherein, The constant pressure water supply assembly (1) comprises a constant pressure water tank (1.1), a water storage tank (1.2) and a water pump (1.3), the constant pressure water tank (1.1) comprises an outer cylinder (1.1.1) and an inner cylinder (1.1.2), the outer cylinder (1.1.1) is arranged above the measuring soil column container (2), the bottom of the outer cylinder (1.1.1) is communicated with the water storage tank (1.2) through a pipeline; the inner cylinder (1.1.2) is arranged in the outer cylinder (1.1.1), and the inner cylinder (1.1.2) is communicated with the water storage tank (1.2) and the water inlet (2.1.10) through pipelines respectively; the water pump (1.3) is arranged on the pipeline between the inner cylinder (1.1.2) and the water storage tank (1.2).

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