CN110595984A - A cylinder infiltrator for measuring saturated hydraulic conductivity of undisturbed soil and its measuring method - Google Patents

Abstract

The invention discloses a cylinder infiltration instrument for measuring the saturated hydraulic conductivity of undisturbed soil and a measuring method thereof. The cylinder infiltration instrument includes a cylinder, a top plate, a partition, an exhaust pipe and a water outlet pipe, and the top plate is sealed and installed on the cylinder. On the top of one end of the cylinder, the partition is sealed and installed on the upper part of the other end of the cylinder. One end of the exhaust pipe is pierced on the top plate, and the other end of the exhaust pipe is connected to the partition. There is a vent hole on the exhaust pipe, and the outlet pipe runs through Installed on the partition, the nozzle of the exhaust pipe is equipped with an exhaust valve, the nozzle of the outlet pipe is installed with a water stop valve, the top plate is equipped with a water inlet and a rubber plug, and the bottom of the cylinder is installed with a water-permeable pad. There is a scale on the side wall of the cylinder. The infiltration meter has a simple structure and can quickly and accurately measure the saturated hydraulic conductivity of the undisturbed soil, so as to solve the problems of cumbersome operation and low accuracy of the existing hydraulic conductivity measurement devices. The calculation results of the method are not disturbed by too many factors, and the phenomenon that the accuracy deviation of the calculation results of hydraulic conductivity K _s is too large due to the doping of various data is avoided.

Description

A cylinder infiltrator for measuring saturated hydraulic conductivity of undisturbed soil and its measuring method

technical field

The invention relates to the technical field of soil hydrodynamic parameter measurement, in particular to a cylinder infiltration meter for measuring the saturated hydraulic conductivity of undisturbed soil and a measuring method thereof.

Background technique

Soil infiltration is an inherent property of soil, which is closely related to soil erosion, soil erosion, crop irrigation management, and solute transport. Many scholars believe that the measurement of soil infiltration performance is an indicator of soil properties, and soil saturated hydraulic conductivity K _s is not only a quantitative index reflecting soil water permeability, but also an indispensable physical parameter in seepage calculation. Usually K _s can not be obtained by calculation, but can only be determined by experiment, and its determination methods can be divided into two categories: indoor test and field test. The indoor test is simple and easy to do, but due to the unavoidable disturbance during sampling, it is generally difficult to obtain representative undisturbed soil samples, especially coarse-grained soils such as sandy soil, so the obtained K _s often cannot reflect the undisturbed soil well. actual water permeability. The field test is more accurate than the K _s data obtained from the indoor test, but the field determination of K _s is still a big problem in the study of soil hydrodynamics. At present, the more successful methods are the double-ring method and the disc method. The double-ring method is a method of measuring K _s based on Darcy’s law using a double-ring infiltration instrument. During the test, the infiltration ring is tapped into the soil, and water is added to the annular space between the inner ring and the inner and outer rings respectively to keep the inner ring and the outer ring. The water level in the ring seepage cylinder is constant and the height is consistent. The inner ring is used to measure the infiltration under constant water head, and the annular space between the inner and outer rings is used as a buffer zone to prevent the horizontal diffusion of infiltration water. This method generates vibrations during the process of knocking the infiltration ring into the soil, which may easily cause separation of the ring and the soil, gaps, and damage to the original soil structure, resulting in large measurement results. The disk method is a method of measuring Ks based on the principle of negative pressure infiltration using a disk infiltration meter. During the test, firstly, fine sand needs to be flattened to keep the bottom of the disk in good contact with the soil; secondly, the negative pressure water head needs to be adjusted. To meet the negative pressure infiltration conditions; at the end of the test, quickly remove the disc infiltration instrument, extract the surface soil, and measure the soil moisture content; it can be seen that the disc method test design is more complicated, and the actual operation is more cumbersome. Therefore, It has become an urgent problem to seek a relatively simple, fast and accurate method to measure the saturated hydraulic conductivity of undisturbed soil.

Contents of the invention

The purpose of the present invention is to provide a cylinder infiltrator for measuring the saturated hydraulic conductivity of undisturbed soil and its measuring method, which can simply, quickly and accurately measure the saturated hydraulic conductivity of undisturbed soil, so as to solve the problem of existing on-site measurement of hydraulic conductivity. The operation of the rate device is cumbersome and the accuracy is not high.

The purpose of the present invention is achieved through the following technical solutions:

A cylinder infiltration instrument for measuring the saturated hydraulic conductivity of undisturbed soil, including a cylinder, a top plate, a partition, an exhaust pipe and a water outlet pipe, the top plate is sealed and installed on the top of one end of the cylinder, and the partition It is sealed and installed on the upper part of the other end of the cylinder, one end of the exhaust pipe is pierced through the top plate, the other end of the exhaust pipe is connected with the partition, and a passageway is opened on the exhaust pipe. Air holes, the water outlet pipe is installed through the partition, the mouth of the exhaust pipe is equipped with an exhaust valve, the mouth of the water outlet pipe is installed with a water stop valve, and the top plate is provided with a water inlet , the water inlet is provided with a sealing rubber plug matched with the water inlet, a water-permeable pad is installed at the bottom of the cylinder, and a scale is provided on the side wall of the cylinder.

Further, the diameter of the water inlet is 2.4-2.8 cm.

Further, the diameters of the exhaust pipe and the water outlet pipe are both 0.5-0.8 cm.

Further, the distance between the ventilation hole and the partition is 0-0.5 cm, and the distance between the partition and the bottom end of the cylinder is 2-2.5 cm.

A method for measuring the undisturbed soil saturated hydraulic conductivity using a cylinder infiltrator measuring the undisturbed soil saturated hydraulic conductivity, comprising the following steps:

S1. Check the air tightness of the cylinder infiltrator: open the exhaust valve of the exhaust pipe, close the water stop valve of the outlet pipe, fill the cylinder with water, close the exhaust valve of the exhaust pipe, and open the water stop Valve, observe the water level change;

S2. Select the test point to install the infiltrator: remove the vegetation and stones at the test point, level the ground, and install the water-filled cylinder infiltrator with good airtightness vertically at the test point;

S3. Record the infiltration experiment data of soil with different textures: open the exhaust valve of the exhaust pipe, record the water level height data of the cylinder at different times until the infiltration stage is stable;

S4. Establish a steady-state model of the saturated hydraulic conductivity K _s of the undisturbed soil: draw the relationship curve between the amount of water in the cylinder and time according to the experimental data, calculate the slope value of the stable infiltration stage according to the slope of the curve, and analyze the data to establish a steady-state model. state model:

Among them, K _s is the saturated hydraulic conductivity of undisturbed soil, D is the diameter of the cylinder, ΔW is the reduction of water in the cylinder, Δt is the time interval, is the slope of the curve;

S5. Calculate the calculated value of soil saturated hydraulic conductivity K _s : calculate the calculated value of soil saturated hydraulic conductivity K _s according to the experimental data and the steady-state model.

Further, the step S1 is specifically:

After the cylinder is filled with water, close the exhaust valve of the exhaust pipe and open the water stop valve. After standing still for a period of time, observe whether the water level in the cylinder can remain constant. If the water level remains constant, it means that the cylinder infiltration instrument is airtight. sex is good.

Further, the step S2 is specifically:

Put the cylinder vertically on the flat ground at the test point, and bury and compact the periphery with soil.

Further, the establishment of a steady-state model in the step S4 is specifically:

S410. According to the principle of water balance, the amount of water entering the soil is equal to the reduction of water in the cylinder, and the obtained water balance formula is:

ΔI=ΔW

Among them, ΔI is the amount of water entering the soil, and ΔW is the reduction of water in the cylinder;

S420. Calculating the reduction of water in the cylinder ΔW: observe the scale value of the water level change in the cylinder to calculate ΔW:

Wherein, D is the diameter _of the cylinder, and X1 and X2 are the scale readings of water levels at different times _;

S430. Draw a relationship curve between the amount of water reduction in the cylinder and time: analyze the slope of the relationship curve The relationship between the saturated hydraulic conductivity K _s of the undisturbed soil and the diameter D of the cylinder is derived and the steady-state model is established:

The beneficial effects of the present invention are:

1) The cylindrical infiltrator for measuring the saturated hydraulic conductivity of the undisturbed soil of the present invention has a simple structure and is easy to manufacture. The water supply unit and the water seepage unit are integrated and are easy to move; Disturbance avoids the phenomenon that there are gaps in the separation of the cylinder and the soil and then destroys the original soil structure, thereby eliminating the phenomenon that the measurement results are too large; the operation is also simple, and it is only necessary to observe the water level changes at different times and accurately record the water level changes. It is more time-saving and labor-saving in the experiment process; its manufacturing price is also low, its management is convenient, and it can be produced on a large scale and popularized and applied in field experiments.

2) The steady-state model of the undisturbed soil saturated hydraulic conductivity K _s of the present invention is based on real-time and accurate experimental data, and after a large amount of experimental data is integrated and quantitatively analyzed, the reduction and time of water in the cylinder are drawn The relationship curve, that is, the relationship curve between the amount of water entering the soil and time, this curve intuitively reveals the difference in the soil infiltration rate of different soil textures in the infiltration process and the soil infiltration rate of the same soil texture in the infiltration process. The change process of cumulative infiltration with time, by analyzing the relationship between these differences, the change process and various related data, obtain the steady state based on the undisturbed soil saturated hydraulic conductivity K _s of the cylinder infiltration instrument of the present invention by mathematical method State model, the steady state model of the present invention only needs to know the change value of the water level at different times, and the saturated hydraulic conductivity K _s of the undisturbed soil can be obtained by calculation. The calculation result is not affected by too many factors. The phenomenon that the accuracy deviation of the calculation result of the water rate K _s is too large, the final test result proves that there is no significant difference between the calculated value and the real value of the saturated hydraulic conductivity K _s of the undisturbed soil, and the consistency is good, which further proves that the cylinder of the present invention The feasibility of the osmometer and its measurement method.

Description of drawings

Fig. 1 is the overall structural diagram of the cylinder infiltration instrument measuring undisturbed soil saturated hydraulic conductivity of the present invention;

Fig. 2 is the flow chart of the measuring method of cylinder infiltrator of the present invention;

Fig. 3 is the relationship curve a between the reduction of water in the cylinder and the time when the cylinder infiltrator of the present invention measures the clay quality;

Fig. 4 is the relationship curve b between the reduction of water in the cylinder and the time when the cylinder infiltration meter of the present invention measures the loam texture;

Fig. 5 is the relation curve c of the reduction of water in the cylinder and time when the cylinder infiltration instrument of the present invention measures the texture of sandy loam;

Fig. 6 is the relationship curve d between the reduction of water in the cylinder and the time when the cylinder infiltration meter of the present invention measures the loamy sandy soil quality;

Fig. 7 is the relationship curve e between the reduction of water in the cylinder and the time when the cylinder infiltration meter of the present invention measures the sandy soil quality;

Fig. 8 is the comparison curve of the calculated value and real value of soil saturated hydraulic conductivity of the present invention;

In the figure, 1-cylinder, 2-top plate, 3-baffle, 4-exhaust pipe, 401-exhaust valve, 5-outlet pipe, 501-water stop valve, 6-air vent, 7-water inlet, 8-sealing rubber plug, 9-permeable pad, 10-scale.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Apparently, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts belong to the protection scope of the present invention.

Example 1

Referring to Figures 1-8, the present invention provides a technical solution:

Please refer to Fig. 1, a kind of cylinder infiltration instrument for measuring undisturbed soil saturated hydraulic conductivity, comprises cylinder 1, top board 2, dividing plate 3, exhaust pipe 4 and outlet pipe 5, and described top board 2 is sealed and installed on the place The top of one end of the cylinder 1, the partition plate 3 is sealed and installed on the other end of the cylinder 1, one end of the exhaust pipe 4 is pierced through the top plate 2, and the other end of the exhaust pipe 4 One end is connected to the partition 3, the exhaust pipe 4 is provided with a vent hole 6, the outlet pipe 5 is installed through the partition 3, and the mouth of the exhaust pipe 4 is equipped with an exhaust Valve 401, the mouth of the outlet pipe 5 is equipped with a water stop valve 501, the top plate 2 is provided with a water inlet 7, and the water inlet 7 is provided with a sealing rubber plug 8 that cooperates with the water inlet 7. A water-permeable pad 9 is installed at the bottom of the cylinder 1 , and a scale 10 is provided on the side wall of the cylinder 1 .

Further, the diameter of the water inlet 7 is 2.4-2.8 cm.

Further, the diameters of the exhaust pipe 4 and the water outlet pipe 5 are both 0.5-0.8 cm.

Further, the distance between the vent hole 6 and the partition 3 is 0-0.5 cm, and the distance between the partition 3 and the bottom end of the cylinder 1 is 2-2.5 cm.

Preferably, a cylinder infiltrator with the specifications shown in Table 1.1 can be made

The manufacture process of the cylindrical infiltration instrument of the above-mentioned preferred embodiment is: the nozzle of the intake pipe near the end of the dividing plate 3 is opened with an air hole 6, and the distance between the air hole 6 and the dividing plate 3 is 0.5 centimeters. The other end is pierced with the top plate 2 and the contact with the top plate 2 is sealed with a sealing ring. The partition plate 3 is sealed and installed near the bottom end of the cylinder 1. The distance between the partition plate 3 and the bottom end of the cylinder 1 is 2 cm. The top plate 2 Set up water inlet 7, a rubber plug can be inserted into the water inlet 7 to seal, water outlet pipe 5 is set on partition 3, switch valves are installed on outlet pipe 5 and exhaust pipe 4, scales can be pasted on the side wall of cylinder 1 Foot 10.

The cylindrical infiltration instrument for measuring the saturated hydraulic conductivity of undisturbed soil of the present invention has a simple structure, is easy to manufacture, and has easy-to-obtain materials. The water supply unit and the water seepage unit are integrated to facilitate movement; Disturbance avoids the phenomenon that the cylinder 1 and the soil are separated to form gaps and then destroy the original soil structure, thereby eliminating the phenomenon that the measurement result is too large; the operation is also simple, and it is only necessary to observe the water level change at different times and accurately record the water level change value. The method saves time and labor in the experiment process; the manufacturing price is also low, the management is convenient, and the method can be produced in a large scale and popularized and applied in field experiments.

The measuring method of the cylinder infiltrator for measuring the saturated hydraulic conductivity of the undisturbed soil comprises the following steps:

S1. Check the air tightness of the cylinder infiltrator: open the exhaust valve of the exhaust pipe, close the water stop valve of the outlet pipe, fill the cylinder with water, close the exhaust valve of the exhaust pipe, and open the water stop Valve, observe the water level change;

Specifically, after the cylinder is filled with water, close the exhaust valve 401 of the exhaust pipe 4 and open the water stop valve 501. After standing still for a period of time, observe whether the water level in the cylinder can remain constant. The airtightness of the cylinder infiltrator is good.

S2. Select the test point to install the infiltrator: remove the vegetation and stones at the test point, level the ground, and install the water-filled cylinder infiltrator with good airtightness vertically at the test point;

Specifically, the cylinder was placed vertically on the flat ground at the test point, and the periphery was buried and compacted with soil.

The soil is not disturbed when the cylinder infiltrator is installed by the above method, which avoids the phenomenon that the cylinder 1 and the soil are separated to form a gap and destroy the original soil structure, thereby preventing the phenomenon that the measurement result is too large.

S3. Record the infiltration experiment data of soil with different textures: open the exhaust valve 401 of the exhaust pipe 4, record the water level height data of the cylinder 1 at different times until the infiltration stage is stable;

S4. Establish a steady-state model of the saturated hydraulic conductivity K _s of the undisturbed soil: draw the relationship curve between the amount of water reduction in the cylinder 1 and time according to the experimental data, calculate the slope value of the stable infiltration stage according to the slope of the curve, and analyze the data to establish Steady state model:

Among them, K _s is the saturated hydraulic conductivity of undisturbed soil, D is the diameter of cylinder 1, ΔW is the reduction of water in cylinder 1, Δt is the time interval, is the slope of the curve;

Specifically, the specific process of establishing a steady-state model in the step S4 is:

S410. According to the principle of water balance, the amount of water entering the soil is equal to the reduction of water in the cylinder 1, and the obtained water balance formula is:

ΔI=ΔW

Among them, ΔI is the amount of water entering the soil, and ΔW is the reduction of water in the cylinder 1;

S420. Calculating the water reduction ΔW in the cylinder 1: Observing the scale value of the water level change in the cylinder 1 to calculate ΔW:

Wherein, D is cylinder 1 diameter, and X ₁ and X ₂ are the scale readings of water levels at different times respectively;

Only by measuring the change value of the water level of the cylinder 1 through the scale 10, the reduction of water in the cylinder can be obtained, and then the amount of water entering the soil can be obtained.

S430. Draw a relationship curve between the amount of water reduction in the cylinder and time: analyze the slope of the relationship curve The relationship between the saturated hydraulic conductivity K _s of the undisturbed soil and the diameter D of the cylinder is derived and the steady-state model is established:

S5. Calculate the calculated value of soil saturated hydraulic conductivity K _s : calculate the calculated value of soil saturated hydraulic conductivity K _s according to the experimental data and the steady-state model.

experiment analysis:

The present invention is by making the cylinder infiltration instrument that diameter is 4 centimeters, 8 centimeters, 12 centimeters and 16 centimeters, utilizes large-diameter cylinder to take the undisturbed soil of field, according to above-mentioned measurement method, makes each cylinder infiltration instrument successively Put it in the center of the large-diameter cylinder, and then carry out the infiltration test of the cylinder infiltration instrument: first place the cylinder infiltration instrument in the center of the soil surface of the large-diameter cylinder, and test the clay texture a, loam texture b, and sand respectively. Five kinds of soil quality of loamy soil quality c, loamy sandy soil quality d and sandy soil quality e carry out infiltration experiment, record the reduction of water in the cylinder of different infiltration time, calculate and derive according to the steady-state model in the measuring method of the present invention The calculated value K _s of the water rate, and then take away the cylinder infiltration instrument, and then conduct a constant head infiltration test on the large-diameter cylinder to obtain the real value K _s . Measurement accuracy, and finally according to the experimental data, draw the relationship curve between the water reduction in the cylinder and time at different times and the comparison curve between the calculated value and the real value of the soil saturated hydraulic conductivity, and the curve shown in Figure 3-8 is obtained:

Please refer to Figure 3-7, comparing the curves of water reduction and time relationship in the cylinder 1 infiltrator with five different soil textures and different pipe diameters, it can be deduced that:

(1) In the early stage of infiltration, the reduction of water in the cylinder and the infiltration time increase in a curve. For a cylinder infiltrator with the same diameter, the curve tends to be gentler with the increase of time; In a cylinder infiltration meter, the reduction of water in the cylinder remains basically constant within the same time interval, that is, the slope of the curve no longer changes, indicating that it is in the steady seepage stage.

(2) The soil texture has a significant impact on the reduction of water in the cylinder. Further analysis found that in the late stage of infiltration, the slope of the relationship curve between the reduction of water in the cylinder and time It is positively correlated with soil saturated hydraulic conductivity K _s and cylinder diameter, and its related expression can be expressed as:

Finally, as shown in Figure 8, Figure 8 is actually a schematic diagram for verifying the correctness of the steady-state model of this application. According to the steady-state model in the above method, the soil saturated hydraulic conductivity is calculated, and the calculated value of the soil saturated hydraulic conductivity is compared with the real value. The comparison curve between the calculated value of soil saturated hydraulic conductivity and the real value is obtained, and the real value is obtained through the above-mentioned large-diameter constant head infiltration test. The comparison curve shows that the calculated value of soil saturated hydraulic conductivity has no significant difference with the real value, which is consistent The performance is good, which further proves the feasibility of the cylinder infiltrator and its measurement method of the present invention.

The measuring method of the cylinder infiltration instrument measuring undisturbed soil saturated hydraulic conductivity of the present invention, the steady-state model of its undisturbed soil saturated hydraulic conductivity K _s is based on real-time and accurate experimental data, and a large amount of experimental data is carried out After the integration and quantitative analysis, the relationship curve of water reduction in the cylinder and time is drawn, that is, the relationship curve of the amount of water entering the soil and time, which intuitively reveals the soil infiltration of different soil textures during the infiltration process The difference of soil infiltration rate and the change process of cumulative soil infiltration with time during the infiltration process of the same soil texture. The slope of the curve of cumulative infiltration and time is the infiltration rate. By analyzing these differences, change processes and various The relationship between relevant data is obtained by a mathematical method based on the steady-state model of the undisturbed soil saturated hydraulic conductivity K _s of the cylinder infiltrator of the present invention. The steady-state model of the present invention only needs to know the change value of the water level at different times. The saturated hydraulic conductivity K _s of the undisturbed soil is obtained through calculation, and the calculation result is not disturbed by too many factors, which avoids the phenomenon that the accuracy of the calculation result of the hydraulic conductivity K _s is too large due to the doping of various data. The final test results prove that the undisturbed soil There is no significant difference between the calculated value and the real value of saturated hydraulic conductivity K _s , and the consistency is good.

The above descriptions are only preferred embodiments of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and Modifications can be made within the scope of the ideas described herein, by virtue of the above teachings or skill or knowledge in the relevant art. However, changes and changes made by those skilled in the art do not depart from the spirit and scope of the present invention, and should all be within the protection scope of the appended claims of the present invention.

Claims (8)

1. The utility model provides a measure drum infiltration appearance of undisturbed soil saturation hydraulic conductivity which characterized in that: including drum (1), roof (2), baffle (3), blast pipe (4) and outlet pipe (5), roof (2) seal installation is in the one end top of drum (1), baffle (3) seal installation in the other end upper portion of drum (1), the one end of blast pipe (4) is worn to locate roof (2), the other end of blast pipe (4) with baffle (3) are connected, air vent (6) have been seted up on blast pipe (4), outlet pipe (5) run through install in on baffle (3), discharge valve (401) are installed to the mouth of pipe of blast pipe (4), stagnant water valve (501) are installed to the mouth of pipe of outlet pipe (5), be equipped with water inlet (7) on roof (2), water inlet (7) department is equipped with water inlet (7) complex sealed rubber buffer (8), the bottom of drum (1) is installed and is passed through water pad (9), the lateral wall of drum (1) is equipped with scale (10).

2. The cylinder infiltration instrument for measuring undisturbed soil saturated hydraulic conductivity of claim 1, wherein: the diameter of the water inlet (7) is 2.4-2.8 cm.

3. The cylinder infiltration instrument for measuring undisturbed soil saturated hydraulic conductivity of claim 1, wherein: the diameters of the exhaust pipe (4) and the water outlet pipe (5) are both 0.5-0.8 cm.

4. The cylinder infiltration instrument for measuring undisturbed soil saturated hydraulic conductivity of claim 1, wherein: the distance between the vent holes (6) and the partition plates (3) is 0-0.5 cm, and the distance between the partition plates (3) and the bottom ends of the cylinders (1) is 2-2.5 cm.

5. A measuring method of a cylinder infiltration instrument for measuring undisturbed soil saturated hydraulic conductivity is characterized in that the cylinder infiltration instrument for measuring undisturbed soil saturated hydraulic conductivity in claim 1 is adopted for measurement, and the method comprises the following steps:

s1, checking the air tightness of the cylinder infiltration instrument: opening an exhaust valve (401) of an exhaust pipe (4), closing a water stop valve (501) of a water outlet pipe (5), filling water into the cylinder (1), closing the exhaust valve (401), opening the water stop valve (501), and observing water level change;

s2, selecting a test point and installing an infiltration instrument: removing vegetation and stones on the earth surface of the test point, leveling the ground, and vertically installing a water containing cylinder infiltration instrument with good air tightness on the test point;

s3, recording infiltration experimental data of soil with different textures: opening an exhaust valve (401) of the exhaust pipe (4), and recording water level height data of the cylinder (1) at different moments until the infiltration stage is stabilized;

s4, establishing the saturation hydraulic conductivity K of undisturbed soil_sThe steady state model of (c): drawing a relation curve of the reduction amount of water in the cylinder (1) and time according to experimental data, calculating a slope value of a stable infiltration stage according to the slope of the curve, analyzing data and establishing a steady-state model:

wherein, K_sSaturated hydraulic conductivity of undisturbed soil, D is the diameter of the cylinder, delta W is the reduction amount of water in the cylinder, delta t is a time interval,is the slope of the curve;

s5, calculating a soil saturated hydraulic conductivity calculation value K_s: calculating to obtain a calculated value K of the saturated hydraulic conductivity of the soil according to the experimental data and the steady-state model_s。

6. The method for measuring the saturated hydraulic conductivity of undisturbed soil according to claim 5, wherein the method comprises the following steps: the step S1 specifically includes:

after the cylinder (1) is filled with water, the exhaust valve (401) of the exhaust pipe (4) is closed, the water stop valve (501) is opened, whether the water level in the cylinder can be kept constant or not is observed after the cylinder is kept static for a period of time, and if the water level is kept constant, the cylinder infiltration instrument is good in air tightness.

7. The method for measuring the saturated hydraulic conductivity of undisturbed soil according to claim 1, wherein the method comprises the following steps: the step S2 specifically includes:

the cylinder (1) is vertically placed on the flat ground of the test point, and the periphery is buried and compacted by soil.

8. The method for measuring the saturated hydraulic conductivity of undisturbed soil according to claim 1, wherein the method comprises the following steps: the establishing of the steady-state model in the step S4 specifically includes:

s410, according to the water quantity balance principle, the water quantity entering the soil is equal to the reduction quantity of the water in the cylinder (1), and the obtained water quantity balance formula is as follows:

ΔI＝ΔW

wherein, Delta I is the water amount entering the soil, and Delta W is the reduction amount of the water in the cylinder (1);

s420, calculating the reduction amount delta W of water in the cylinder: calculating the Delta W according to the scale value of the water level change in the observation cylinder (1):

wherein D is the diameter of the cylinder (1) and X₁And X₂Respectively reading the scales of the water levels at different times;

s430, drawing a relation curve of the reduction amount of water in the cylinder and time: analysis of the slope of the relationshipSaturated hydraulic conductivity K of undisturbed soil_sAnd the diameter D of the cylinder (1), the relationship being derivedAnd establishing a steady-state model: