Field aeration zone soil layer vertical permeability coefficient in-situ testing device and method

Abstract

The invention discloses a field aeration zone soil layer vertical permeability coefficient in-situ testing device and method, and relates to the technical field of porous material permeability testing, the field aeration zone soil layer vertical permeability coefficient in-situ testing device comprises an outer ring, an inner ring, an outer ring water injection device and an inner ring water injection device, the outer ring and the inner ring are used for being pressed into an aeration zone soil layer, the inner ring is sleeved with the outer ring, and the outer ring and the inner ring are coaxially arranged; the outer ring water injection device comprises a first water bucket and a first volumetric flask which are connected through a first pipeline, a first water pump is arranged on the first pipeline, the first volumetric flask is communicated with an annular space between the outer ring and the inner ring through a first water conveying pipe, and a first control valve is arranged on the first water conveying pipe; the inner ring water injection device comprises a second bucket and a second volumetric flask which are connected through a second pipeline, a second water pump is arranged on the second pipeline, the second volumetric flask is communicated with the inner ring internal space through a second water conveying pipe, and a second control valve is arranged on the second water conveying pipe. According to the invention, the vertical permeability coefficient of the aeration zone soil layer can be accurately and quickly obtained.

Description

Technical Field

[0001] The invention relates to the technical field of testing the permeability of porous materials, and in particular to an in-situ testing device and method for the vertical permeability coefficient of a field aeration zone soil layer. Background Art

[0002] The soil layer of the vadose zone is an important channel for atmospheric precipitation, rivers, etc. to replenish groundwater, and it is also the only way for ground pollution sources (such as pesticides, fertilizers, human and animal excretion, etc.) to enter the underground aquifer. The vertical permeability coefficient of the vadose zone soil plays an important role in the above process. Different fields have different requirements for the vertical permeability coefficient of the vadose zone soil layer. For example, the environmental field requires the vertical permeability coefficient of the vadose zone soil layer to be smaller for non-point source pollution areas, so as to prevent pollutants from entering the underground aquifer; while the groundwater field hopes that the vertical permeability coefficient of the vadose zone soil layer is larger, so as to increase the impact of precipitation and surface water on groundwater. Therefore, how to obtain the vertical permeability coefficient of the vadose zone soil layer accurately and quickly has become increasingly important in many fields. Summary of the invention

[0003] The purpose of the present invention is to provide a field in-situ testing device and method for the vertical permeability coefficient of the soil layer in the vadose zone, so as to solve the problems existing in the above-mentioned prior art and to accurately and quickly obtain the vertical permeability coefficient of the soil layer in the vadose zone.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] The present invention provides an in-situ testing device for the vertical permeability coefficient of a soil layer in a field aeration zone, comprising an outer ring, an inner ring, an outer ring water injection device and an inner ring water injection device, wherein the outer ring and the inner ring are used for pressing into the soil layer in the aeration zone, the outer ring is sleeved outside the inner ring and the two are coaxially arranged; the outer ring water injection device comprises a first water bucket and a first volumetric bottle connected by a first pipeline, the first pipeline is provided with a first water pump, which is used to pump water in the first water bucket into the first volumetric bottle, the first volumetric bottle is connected to the annular space between the outer ring and the inner ring through a first water delivery pipe, and the first water delivery pipe is provided with a first control valve; the inner ring water injection device comprises a second water bucket and a second volumetric bottle connected by a second pipeline, the second pipeline is provided with a second water pump, which is used to pump water in the second water bucket into the second volumetric bottle, the second volumetric bottle is connected to the internal space of the inner ring through a second water delivery pipe, and the second water delivery pipe is provided with a second control valve.

[0006] Preferably, it also includes a first lifting base and a second lifting base, the first lifting base is fixedly provided with a first column, the first volumetric flask is placed on the first lifting base and fixed to the first column through a first hoop; the second lifting base is fixedly provided with a second column, the second volumetric flask is placed on the second lifting base and fixed to the second column through a second hoop.

[0007] Preferably, a first water level monitoring alarm and a second water level monitoring alarm of the same height are respectively provided on the inner walls of the outer ring and the inner ring, which are respectively used to monitor the water levels of the outer ring and the inner ring and to issue an alarm when the water levels exceed the water level threshold position.

[0008] Preferably, the first volumetric flask and the second volumetric flask are both organic glass volumetric flasks.

[0009] Preferably, the first pipeline, the first water pipe, the second pipeline and the second water pipe are all hoses.

[0010] The present invention also provides a method for in-situ testing the vertical permeability coefficient of a field aeration zone soil layer, using the above-mentioned in-situ testing device for the vertical permeability coefficient of a field aeration zone soil layer, comprising the following steps:

[0011] S1: Select a test site, dig a test infiltration pit and level the bottom of the pit, press the outer ring and the inner ring into the soil layer of the aeration zone in the test infiltration pit, and lay a layer of gravel on the bottom of the outer ring and the inner ring;

[0012] S2: injecting water into the outer ring through the outer ring water injection device and obtaining the outer ring water injection volume; injecting water into the inner ring through the inner ring water injection device and obtaining the inner ring water injection volume; the inner and outer ring water injections shall be carried out simultaneously and the water levels of the inner and outer rings shall be kept consistent;

[0013] S3: According to the water injection volume of the inner ring and the outer ring, the permeability coefficient of the vadose zone soil layer is obtained by the following formula:

[0014]

[0015] In the formula: K is the permeability coefficient of the test soil layer, cm / s; Q is the water injection volume of the inner ring, L / min; r is the radius of the inner ring, cm; h is the depth of the water surface in the test infiltration pit, cm; L is the capillary rise height of the soil layer in the vadose zone, cm; d is the penetration depth of the water injection test, cm.

[0016] Preferably, in step S3, the water injection test penetration depth d is obtained in the following manner: after the test, the water in the test infiltration pit is drained and the pit is excavated downwards until a relatively dry soil layer is reached, and the water injection test penetration depth d is measured and determined.

[0017] Preferably, in step S2, the water injection volume of the outer ring is obtained by the first volumetric flask, and the water injection volume of the inner ring is obtained by the second volumetric flask; after water injection, the water volume is measured every 10 minutes, and measured continuously for 3 times; then the water volume is measured every 15 minutes, and measured continuously for 2 times; then the water volume is measured every 30 minutes, and when the difference between the water injection volumes measured for 2 consecutive times is not greater than 10% of the water injection volume measured for the last time, the water injection volume measured for the last time is used as the final water injection volume of the inner ring and the outer ring.

[0018] Preferably, in step S3, Q, h, d, r and L measured in the field test are input into a computer data analysis applet, and the computer automatically processes and analyzes the data according to the formula, and generates a report, so as to quickly obtain the permeability coefficient K of the vadose zone soil in the field, determine whether there is an abnormal situation, and promptly notify the user for processing, and determine the accuracy of the results while testing and analyzing based on the test results in the field, and adjust the test plan while testing.

[0019] Preferably, a first water level monitoring alarm and a second water level monitoring alarm of the same height are respectively provided on the inner walls of the outer ring and the inner ring. When the water level exceeds the water level threshold position, the first water level monitoring alarm and the second water level monitoring alarm emit an alarm sound, and the controller controls the first control valve and the second control valve to close. When the water level drops below the water level threshold position, the controller controls the first control valve and the second control valve to open.

[0020] Compared with the prior art, the present invention has achieved the following technical effects:

[0021] The in-situ testing device and method for the vertical permeability coefficient of the soil layer in the field aeration zone provided by the present invention can respectively achieve the purpose of injecting water into the outer ring and the inner ring through the outer ring water injection device and the inner ring water injection device, and can conveniently and accurately control the water level heights of the inner and outer rings, and accurately obtain the outer ring water injection volume and the inner ring water injection volume, thereby accurately and quickly obtaining the vertical permeability coefficient of the soil layer in the aeration zone. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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 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 work.

[0023] Figure 1 A schematic structural diagram of an in-situ testing device for vertical permeability coefficient of aerated zone soil layer in the field provided by the present invention.

[0024] In the figure: 1-outer ring, 2-inner ring, 3-outer ring water injection device, 31-first pipeline, 32-first water bucket, 33-first volumetric flask, 34-first water pump, 35-first water pipe, 36-first control valve, 37-first volumetric flask liquid level sensor, 4-inner ring water injection device, 41-second pipeline, 42-second water bucket, 43-second volumetric flask, 44-second water pump, 45-second water pipe, 46-second control valve, 47-second volumetric flask liquid level sensor, 5-vadose zone soil layer, 6-first lifting base, 7-second lifting base, 8-first column, 9-first hoop, 10-second column, 11-second hoop, 12-first water level monitoring alarm, 13-second water level monitoring alarm, 14-pebbles, 15-first switch, 16-second switch, 17-scale, 18-ground, 19-water surface with inner and outer rings kept consistent. DETAILED DESCRIPTION

[0025] 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.

[0026] The purpose of the present invention is to provide a field in-situ testing device and method for the vertical permeability coefficient of a vadose zone soil layer, so as to solve the problems existing in the prior art and to accurately and quickly obtain the vertical permeability coefficient of the vadose zone soil layer.

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] like Figure 1As shown, this embodiment provides an in-situ test device for the vertical permeability coefficient of aeration zone soil layer in the field, comprising an outer ring 1, an inner ring 2, an outer ring water injection device 3 and an inner ring water injection device 4, the outer ring 1 and the inner ring 2 are used to press into the aeration zone soil layer 5, the outer ring 1 is sleeved outside the inner ring 2 and the two are coaxially arranged; the outer ring water injection device 3 comprises a first water bucket 32 ​​and a first volumetric bottle 33 connected by a first pipeline 31, the first pipeline 31 is provided with a first water pump 34, which is used to pump the water in the first water bucket 32 ​​into the first volumetric bottle 33 The first volumetric bottle 33 is connected to the annular space between the outer ring 1 and the inner ring 2 through the first water pipe 35, and the first water pipe 35 is provided with a first control valve 36; the inner ring water injection device 4 includes a second water bucket 42 and a second volumetric bottle 43 connected through a second pipeline 41, and the second pipeline 41 is provided with a second water pump 44, which is used to pump the water in the second water bucket 42 into the second volumetric bottle 43, and the second volumetric bottle 43 is connected to the internal space of the inner ring 2 through the second water pipe 45, and the second water pipe 45 is provided with a second control valve 46.

[0029] When in use, the outer ring 1 and the inner ring 2 are pressed into the aeration zone soil layer 5, and the two are ensured to be coaxial. The water in the first water bucket 32 ​​is pumped into the first volumetric bottle 33 by the first water pump 34, and the first water pump 34 is provided with a first switch 15. The water in the second water bucket 42 is pumped into the second volumetric bottle 43 by the second water pump 44, and the second water pump 44 is provided with a second switch 16. By manipulating the first control valve 36 and the second control valve 46, the water injection process into the outer ring 1 and the water injection process into the inner ring 2 are controlled respectively, so as to keep the water level heights of the inner ring and the outer ring consistent. Figure 1 The inner and outer rings maintain a consistent water surface 19, and the first volumetric bottle 33 and the second volumetric bottle 43 are both provided with scales 17. The outer ring water injection amount is obtained by observing the scale value of the first volumetric bottle 33, and the inner ring water injection amount is obtained by observing the scale value of the second volumetric bottle 43. The permeability coefficient of the soil layer in the air-filled zone is calculated according to the formula. Through the outer ring water injection device 3 and the inner ring water injection device 4, the purpose of injecting water into the outer ring 1 and the inner ring 2 can be achieved respectively, and the water level height of the inner and outer rings can be conveniently and accurately controlled, and the outer ring water injection amount and the inner ring water injection amount can be accurately obtained, so as to accurately and quickly obtain the vertical permeability coefficient of the soil layer in the air-filled zone.

[0030] In this embodiment, a first lifting base 6 and a second lifting base 7 are also included. A first column 8 is fixedly disposed on the first lifting base 6. A first volumetric bottle 33 is placed on the first lifting base 6 and fixed to the first column 8 through a first hoop 9. A second column 10 is fixedly disposed on the second lifting base 7. A second volumetric bottle 43 is placed on the second lifting base 7 and fixed to the second column 10 through a second hoop 11. The heights of the first volumetric bottle 33 and the second volumetric bottle 43 can be adjusted respectively by the first lifting base 6 and the second lifting base 7, so that water in the first volumetric bottle 33 and the second volumetric bottle 43 can automatically flow into the outer ring 1 and the inner ring 2 under the action of gravity, thereby achieving the purpose of water injection.

[0031] In this embodiment, a first water level monitoring alarm 12 and a second water level monitoring alarm 13 of the same height are respectively provided on the inner walls of the outer ring 1 and the inner ring 2, which are respectively used to monitor the water levels of the outer ring 1 and the inner ring 2, and to issue an alarm when the water level exceeds the water level threshold position to remind the tester to make timely adjustments.

[0032] In this embodiment, the first volumetric flask 33 and the second volumetric flask 43 are both organic glass volumetric flasks.

[0033] In this embodiment, the first pipeline 31 , the first water pipe 35 , the second pipeline 41 and the second water pipe 45 are all hoses.

[0034] A method for in-situ testing the vertical permeability coefficient of a field aeration zone soil layer, using the above-mentioned in-situ testing device for the vertical permeability coefficient of a field aeration zone soil layer, comprises the following steps:

[0035] S1: Select a test site, remove the surface soil 18, dig a square test infiltration pit and level the bottom of the pit, press the outer ring 1 and the inner ring 2 into the aeration zone soil layer 5 in the test infiltration pit, and lay a layer of gravel 14 on the bottom of the outer ring 1 and the inner ring 2 to prevent the soil layer from being eroded during water injection;

[0036] S2: inject water into the outer ring 1 through the outer ring water injection device 3, and obtain the outer ring water injection volume; inject water into the inner ring 2 through the inner ring water injection device 4, and obtain the inner ring water injection volume; the inner and outer rings need to be injected at the same time, and the water levels of the inner and outer rings should be kept consistent;

[0037] S3: According to the water injection volume of the inner ring and the outer ring, the permeability coefficient of the vadose zone soil layer is obtained by the following formula:

[0038]

[0039] In the formula: K is the permeability coefficient of the test soil layer, cm / s; Q is the water injection volume of the inner ring, L / min; r is the radius of the inner ring, cm; h is the depth of the water surface in the test infiltration pit, cm; L is the capillary rise height of the soil layer in the air-filling zone (which can be measured according to the SL237 geotechnical test procedures or take empirical values), cm; d is the penetration depth of the water injection test, cm.

[0040] In step S3, the water injection test penetration depth d is obtained in the following manner: after the test is completed, the water in the test infiltration pit is drained and the pit is excavated downward until a relatively dry soil layer is reached, and the water injection test penetration depth d is measured and determined.

[0041] In step S2, the outer ring water injection amount is obtained by observing the scale value of the first volumetric bottle 33, and the inner ring water injection amount is obtained by observing the scale value of the second volumetric bottle 43; after water injection, the water volume is measured every 10 minutes, and the measurement is continuous for 3 times; then the water volume is measured every 15 minutes, and the measurement is continuous for 2 times; then the water volume is measured every 30 minutes. When the difference between the two consecutive measured water injection amounts is not greater than 10% of the last measured water injection amount, the last measured water injection amount is used as the final inner ring water injection amount and outer ring water injection amount.

[0042] In step S3, Q, h, d, r and L measured in the field test are input into a computer data analysis applet, and the computer automatically processes and analyzes the data according to the formula and generates a report. The permeability coefficient K of the vadose zone soil is quickly obtained in the field, and it is determined whether there is an abnormal situation, and the user is notified in time to handle it. The accuracy of the test results is determined while testing and analyzing in the field, and the test plan is adjusted while testing.

[0043] During the test, when the water level exceeds the water level threshold position, the first water level monitoring alarm 12 and the second water level monitoring alarm 13 sound an alarm, and the controller controls the first control valve 36 and the second control valve 46 to close; when the water level drops below the water level threshold position, the controller controls the first control valve 36 and the second control valve 46 to open, thereby realizing automatic control of the water injection process and effectively reducing human operation errors in the field.

[0044] The device is designed with a modular structure, and each module can be quickly disassembled and replaced, which is convenient for carrying and rapid on-site deployment.

[0045] In this device, high-precision pressure sensors and water level sensors are integrated in the inner ring 2 and the outer ring 1, which can monitor small changes in water level and pressure in real time and improve the accuracy of data.

[0046] The device is equipped with a data acquisition system, which can collect the water level data detected by the first water level monitoring alarm 12 and the second water level monitoring alarm 13 in real time to reduce human errors. A first volumetric bottle level sensor 37 is set in the first volumetric bottle 33, and a second volumetric bottle level sensor 47 is set in the second volumetric bottle 43. The first volumetric bottle level sensor 37 and the second volumetric bottle level sensor 47 transmit the measured liquid level value to the computer terminal through wireless transmission. After the data is obtained through a laptop computer in the field, the water injection volume can be obtained through a data processing applet, and the water injection volume can be automatically recorded to improve the accuracy of the data.

[0047] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An in-situ test device for vertical permeability coefficient of soil layer in aeration zone in the field, characterized by: It includes an outer ring, an inner ring, an outer ring water injection device and an inner ring water injection device, the outer ring and the inner ring are used to press into the soil layer of the air-filling zone, the outer ring is sleeved outside the inner ring and the two are coaxially arranged; the outer ring water injection device includes a first water bucket and a first volumetric bottle connected by a first pipeline, the first pipeline is provided with a first water pump, which is used to pump water in the first water bucket into the first volumetric bottle, the first volumetric bottle is connected to the annular space between the outer ring and the inner ring through a first water pipe, and the first water pipe is provided with a first control valve; the inner ring water injection device includes a second water bucket and a second volumetric bottle connected by a second pipeline, the second pipeline is provided with a second water pump, which is used to pump water in the second water bucket into the second volumetric bottle, the second volumetric bottle is connected to the internal space of the inner ring through a second water pipe, and the second water pipe is provided with a second control valve.

2. The in-situ testing device for vertical permeability coefficient of aerated zone soil layer in the field according to claim 1 is characterized by: It also includes a first lifting base and a second lifting base, wherein a first column is fixedly arranged on the first lifting base, and the first volumetric bottle is placed on the first lifting base and fixed to the first column via a first hoop; a second column is fixedly arranged on the second lifting base, and the second volumetric bottle is placed on the second lifting base and fixed to the second column via a second hoop.

3. The in-situ testing device for vertical permeability coefficient of aerated zone soil layer in the field according to claim 1 is characterized by: The inner walls of the outer ring and the inner ring are respectively provided with a first water level monitoring alarm and a second water level monitoring alarm of the same height, which are used to monitor the water levels of the outer ring and the inner ring respectively and issue an alarm when the water level exceeds a water level threshold position.

4. The in-situ testing device for vertical permeability coefficient of aerated zone soil layer in the field according to claim 1, characterized in that: The first volumetric flask and the second volumetric flask are both organic glass volumetric flasks.

5. The in-situ testing device for vertical permeability coefficient of aerated zone soil layer in the field according to claim 1, characterized in that: The first pipeline, the first water pipe, the second pipeline and the second water pipe are all hoses.

6. A method for in-situ testing the vertical permeability coefficient of a field aeration zone soil layer, characterized in that: The in-situ testing device for vertical permeability coefficient of aerated zone soil layer in the field according to any one of claims 1 to 5 is used, comprising the following steps: S1: Select a test site, dig a test infiltration pit and level the bottom of the pit, press the outer ring and the inner ring into the soil layer of the aeration zone in the test infiltration pit, and lay a layer of gravel on the bottom of the outer ring and the inner ring; S2: injecting water into the outer ring through the outer ring water injection device and obtaining the outer ring water injection volume; injecting water into the inner ring through the inner ring water injection device and obtaining the inner ring water injection volume; the inner and outer ring water injections shall be carried out simultaneously and the water levels of the inner and outer rings shall be kept consistent; S3: According to the water injection volume of the inner ring and the outer ring, the permeability coefficient of the soil layer in the vadose zone is obtained by the following formula: In the formula: K is the permeability coefficient of the test soil layer, cm / s; Q is the water injection volume of the inner ring, L / min; r is the radius of the inner ring, cm; h is the depth of the water surface in the test infiltration pit, cm; L is the capillary rise height of the soil layer in the vadose zone, cm; d is the penetration depth of the water injection test, cm.

7. The method for in-situ testing vertical permeability of aerated zone soil layer in the field according to claim 6, characterized in that: In step S3, the water injection test penetration depth d is obtained in the following manner: after the test is completed, the water in the test infiltration pit is drained and the pit is excavated downward until a relatively dry soil layer is reached, and the water injection test penetration depth d is measured and determined.

8. The method for in-situ testing vertical permeability of aerated zone soil layer in the field according to claim 6, characterized in that: In step S2, the water injection volume of the outer ring is obtained by the first volumetric bottle, and the water injection volume of the inner ring is obtained by the second volumetric bottle; after water injection, the water volume is measured every 10 minutes, and measured continuously for 3 times; then the water volume is measured every 15 minutes, and measured continuously for 2 times; then the water volume is measured every 30 minutes. When the difference between the water injection volumes measured for 2 consecutive times is not greater than 10% of the water injection volume measured for the last time, the water injection volume measured for the last time is used as the final water injection volume of the inner ring and the outer ring.

9. The method for in-situ testing vertical permeability of aerated zone soil layer in the field according to claim 6, characterized in that: In step S3, Q, h, d, r and L measured in the field test are input into a computer data analysis applet, and the computer automatically processes and analyzes the data according to the formula and generates a report. The permeability coefficient K of the vadose zone soil is quickly obtained in the field, and it is determined whether there is an abnormal situation, and the user is notified in time to handle it. The accuracy of the test results is determined while testing and analyzing in the field, and the test plan is adjusted while testing.

10. The in-situ test method for vertical permeability coefficient of aeration zone soil layer in the field according to claim 6, characterized in that: The inner walls of the outer ring and the inner ring are respectively provided with a first water level monitoring alarm and a second water level monitoring alarm of the same height. When the water level exceeds the water level threshold position, the first water level monitoring alarm and the second water level monitoring alarm emit an alarm sound, and the controller controls the first control valve and the second control valve to be closed. When the water level drops below the water level threshold position, the controller controls the first control valve and the second control valve to be opened.

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