CN209327171U - An Experimental Device for Measuring Curve of Unsaturated Soil Permeability Coefficient - Google Patents

Abstract

The utility model discloses a kind of experimental provision for measuring unsaturated soil infiltration coefficient curve, including weighing unit, sample room, liquid-supplying system and data collection systems；Wherein sample room is connected to by rubber tube with liquid-supplying system, and sample room includes chassis and dress sample chamber, and chassis is set at the top of weighing unit, and dress sample chamber is located at the top of chassis, and is fixedly connected with chassis；Data collection system includes moisture meter, tensometer, data collector and computer, in the sample to be tested of moisture meter and tensometer insertion dress sample chamber, data collector is electrically connected with weighing unit, moisture meter, tensometer respectively, and electric signal is sent to computer, by reading moisture content, the matric suction, quality of sample different moments, the infiltration coefficient curve of unsaturated soil is obtained.Above-mentioned experimental provision disclosed by the utility model is easy to operate, measurement accuracy is high, the time is short, the measurement for the various soil properties infiltration coefficient curve in unsaturation that can be encountered suitable for civil engineering.

Description

An Experimental Device for Measuring Curve of Unsaturated Soil Permeability Coefficient

technical field

The utility model relates to the technical field of environmental geotechnical engineering, in particular to an experimental device for measuring the permeability coefficient curve of unsaturated soil.

Background technique

Unsaturated soil refers to soil pores filled with water and air, that is, soil with a saturation between 100 and 0, which is widely distributed on the earth's surface, such as natural sedimentary soil, and most of the soil encountered in geotechnical engineering projects is non-saturated. Saturated soil, in actual environmental geotechnical engineering, rarely encounter saturated soil. Among them, the permeability analysis of unsaturated soil is the basis for the evaluation of soil stability, the analysis of the migration of polluting liquid in soil, and the evaluation of water-proof performance of soil layer. It is closely related to human life, involving water conservancy, environment, transportation, Construction and many other industries.

In 1931, Richards proved through experiments that unsaturated soil conforms to Darcy's law, that is, the seepage velocity of unsaturated water flow is proportional to the total soil water potential, and is related to the distribution of pores in the soil. The vertical one-dimensional Richards The formula is:

Among them, k(θ) is the unsaturated permeability coefficient, indicating the difficulty of fluid passing through the pore skeleton.

At present, the methods used to measure the unsaturated soil permeability coefficient can be divided into steady-state method and unsteady-state method. The measurement range of the steady-state method is relatively small and the measurement time is relatively long. more common.

Therefore, how to provide an experimental device for measuring the unsaturated soil permeability coefficient curve with simple operation, high measurement accuracy and short measurement time is an urgent problem to be solved by those skilled in the art.

Utility model content

In view of this, the utility model provides an experimental device with simple operation, high measurement accuracy and short time, which can be applied to the measurement of permeability coefficient curves of various soils encountered in civil engineering under unsaturated conditions.

In order to achieve the above object, the utility model adopts the following technical solutions:

An experimental device for measuring the permeability coefficient curve of unsaturated soil, including a weighing unit, a sample chamber, a liquid supply system and a data acquisition system;

Wherein the sample chamber communicates with the liquid supply system through a rubber tube, the sample chamber includes a chassis and a sample loading chamber, the chassis is arranged on the top of the weighing unit, the sample loading chamber is located on the top of the chassis, and fixedly connected with the chassis;

The data acquisition system includes a moisture meter, a tensiometer, a data collector and a computer, the moisture meter and the tensiometer are inserted into the sample to be tested in the sample loading cavity, and the data collector is connected with the weighing device respectively. The unit, the moisture meter, and the tensiometer are electrically connected, and the electrical signal is transmitted to the computer, and the permeability coefficient curve of the unsaturated soil is obtained by reading the water content, matrix suction, and mass of the sample at different times.

Preferably, in the above-mentioned experimental device for measuring the unsaturated soil permeability coefficient curve, the side wall of the sample loading chamber is provided with a moisture meter jack and a tensiometer jack, and the moisture meter is inserted into the moisture meter jack The center is sealed with glass glue, and the tensiometer is inserted into the tensiometer socket and sealed with glass glue.

Preferably, in the above-mentioned experimental device for measuring the unsaturated soil permeability coefficient curve, the moisture meter is provided with one, and the tensiometer is provided with two, specifically, the number of the moisture meter and the tensiometer depends on the test device overall height.

Preferably, in the above-mentioned experimental device for measuring the permeability coefficient curve of unsaturated soil, the weighing unit includes an upper metal plate, a lower metal plate and a pressure sensor, and the pressure sensor is fixedly arranged on the upper metal plate and the Between the metal plates mentioned below, it is connected with the said data collector arranged outside, and the weighing data can be displayed.

Preferably, in the above-mentioned experimental device for measuring the permeability coefficient curve of unsaturated soil, the materials of the upper metal plate and the lower metal plate are all aluminum alloys, and the aluminum alloy has small material density, light weight with the same volume, and high strength. High, not easy to corrode advantages.

Preferably, in the above-mentioned experimental device for measuring the permeability coefficient curve of unsaturated soil, the weighing unit is provided with a balance adjustment device.

Preferably, in the above-mentioned experimental device for measuring the unsaturated soil permeability coefficient curve, the lower metal plate is provided with a threaded hole, and the threaded hole is matched with an adjusting and balancing screw, and the adjustment of the adjusting and balancing screw makes the The weighing unit is in a horizontal state, making the measurement data more accurate.

Preferably, in the above-mentioned experimental device for measuring the permeability coefficient curve of unsaturated soil, the liquid supply system includes a liquid storage bottle and a support, the liquid storage bottle is arranged on the height-adjustable support, and the There is a liquid outlet at the bottom of the liquid storage bottle, and the height of the liquid storage bottle is adjusted through the bracket to control the water head, so that the sample in the sample chamber is fully saturated.

Preferably, in the above-mentioned experimental device for measuring the permeability coefficient curve of unsaturated soil, a groove is arranged on the top of the chassis, and a permeable stone and filter paper are arranged in the groove, and the filter paper is located on the top of the permeable stone. Among them, the permeable stone can provide a horizontal surface for the sample, and the permeable stone itself can pass water, thereby saturating the samples in the sample chamber; the filter paper is placed on the permeable stone, which can prevent the samples in the sample chamber from entering the permeable stone and blocking the permeable stone, which can Prevent the failure of the permeable stone and ensure the accuracy of the measured experimental data.

Preferably, in the above-mentioned experimental device for measuring the permeability coefficient curve of unsaturated soil, the shape and size of the groove, the permeable stone and the filter paper are the same.

Preferably, in the above-mentioned experimental device for measuring the permeability coefficient curve of unsaturated soil, a screw channel is provided at the bottom of the groove, and the screw channel is divided into different heights.

Among them, the threaded channel and the groove are arranged alternately. The threaded channel is cylindrical with different diameters. The different heights are because the bottom surface of the groove has a certain angle of inclination. The upper top surface of the cylinder is at the same height (in order to place the permeable stone horizontally), so the screw channels are set at different heights.

Preferably, in the above-mentioned experimental device for measuring the permeability coefficient curve of unsaturated soil, the outer ring of the groove is provided with a sealing ring, preferably a rubber sealing ring, and the function of the sealing ring is to connect the chassis and the sample chamber with screws After the connection is fixed, prevent moisture from flowing out of the connection between the two during saturation.

Preferably, in the above-mentioned experimental device for measuring the permeability coefficient curve of unsaturated soil, a supplementary drain is provided on the side of the chassis, which can be used to enter liquid or discharge liquid. The lowest first-order communication of the above-mentioned threaded channel is used for the circulation of liquid.

Preferably, in the above-mentioned experimental device for measuring the permeability coefficient curve of unsaturated soil, the sample loading chamber and the outer ring of the chassis are provided with fixing screw holes at equal intervals, and the fixing screws pass through the fixing screw holes, The sealed and fixed connection between the sample loading chamber and the chassis is realized so that they are integrated.

Preferably, in the above-mentioned experimental device for measuring the unsaturated soil permeability coefficient curve, a fan is also included, and the height of the fan is equal to the surface of the sample chamber. the same height. The setting of the fan can accelerate the flow of air on the surface of the sample chamber, thereby accelerating the evaporation of the sample in the sample chamber, and the placement of the fan position can accelerate the flow of air near the sample chamber to prevent some wind from not blowing to the surface of the sample chamber.

It can be known from the above-mentioned technical solutions that, compared with the prior art, the utility model discloses an experimental device for measuring the permeability coefficient curve of unsaturated soil. The weight change of the whole device is obtained through the pressure sensor of the weighing unit, and the weight change of the whole device is obtained through the moisture meter. , the tensiometer obtains the moisture content and the matrix suction change curve; the fan accelerates the evaporation of the soil sample to be tested, and the data collector is connected to the computer to analyze the data. The operation is simple and the measurement accuracy is high. The utility model is suitable for the problems encountered in civil engineering Determination of permeability coefficient of various soils under unsaturated conditions.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description It is only an embodiment of the utility model, and those skilled in the art can also obtain other drawings according to the provided drawings without creative work.

Accompanying drawing of Fig. 1 is the overall structural representation of the utility model;

Fig. 2 accompanying drawing is the left view of the utility model sample room;

Fig. 3 accompanying drawing is the right side view of the utility model sample room;

The accompanying drawing of Fig. 4 is the top view of the chassis of the utility model.

In the picture:

1 is the liquid storage bottle, 2 is the liquid outlet, 3 is the rubber tube, 4 is the replenishment drain, 5 is the groove, 6 is the chassis, 7 is the fixing screw, 8 is the rubber sealing ring, 9 is the permeable stone, 10 is the Moisture meter, 11 is tensiometer, 12 is sample loading chamber, 13 is fan, 1401 is upper metal plate, 1402 is lower metal plate, 15 is pressure sensor, 16 is balance screw, 17 is data collector, 18 is computer , 19 is a support, 20 is a moisture meter jack, 21 is a tensiometer jack, 22 is a filter paper, and 23 is a fixing screw jack.

Detailed ways

The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the implementations. example. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

The embodiment of the utility model discloses an experimental device with simple operation, high measurement accuracy and short time, which is applicable to the measurement of permeability coefficient curves of various soils encountered in civil engineering under unsaturated conditions.

Referring to the accompanying drawings, the utility model provides an experimental device for measuring the permeability coefficient curve of unsaturated soil, including a weighing unit, a sample chamber, a liquid supply system and a data acquisition system;

Wherein the sample chamber communicates with the liquid supply system through the rubber tube 33, the sample chamber includes a chassis 66 and a sample loading chamber 1212, the chassis 66 is arranged on the top of the weighing unit, and the sample loading chamber 12 is located at the top of the chassis 6 and is fixedly connected to the chassis 6;

The data acquisition system comprises a moisture meter 10, a tensiometer 11, a data collector 17 and a computer 18. The moisture meter 10 and the tensiometer 11 are inserted into the sample to be tested in the sample chamber 12, and the data collector 17 is connected with the weighing unit and the moisture meter respectively. 10. The tensiometer 11 is electrically connected, and the electrical signal is sent to the computer 18 .

In order to further optimize the above-mentioned technical scheme, the side wall of the sample loading chamber 12 is provided with a moisture meter jack 20 and a tensiometer jack 21, and the moisture meter 10 is inserted into the moisture meter jack 20 and sealed with glass glue, and the tensiometer 11 is inserted into the tensiometer insert. The hole 21 is sealed by glass glue.

In order to further optimize the above technical solution, one moisture meter 10 is provided, and two tensiometers 11 are provided.

In order to further optimize the above-mentioned technical scheme, the weighing unit includes an upper metal (aluminum alloy) plate, a lower metal plate 1402 and a pressure sensor 15, and the pressure sensor 15 is fixedly arranged between the upper metal plate 1401 and the lower metal plate 1402, and is arranged outside The data collector 17 is connected, and the data of weighing can be displayed.

In order to further optimize the above technical solution, the weighing unit is provided with a balance adjustment device.

In order to further optimize the above technical solution, the lower metal plate 1402 is provided with a threaded hole, and the threaded hole is matched with a balance screw 16, and the weighing unit is in a horizontal state through the adjustment of the balance screw 16.

In order to further optimize the above-mentioned technical solution, the liquid supply system includes a liquid storage bottle 1 and a bracket 19, the liquid storage bottle 1 is arranged on a height-adjustable bracket 19, and the bottom of the liquid storage bottle 1 is provided with a liquid outlet 22, through the bracket 19 Adjust the height of the liquid storage bottle 1 to control the water head, so that the sample in the sample chamber is fully saturated.

In order to further optimize the above-mentioned technical solution, a groove 5 is arranged on the top of the chassis 6 , and a water-permeable stone 9 and a filter paper 22 are arranged in the groove 5 , and the filter paper 22 is located on the top of the water-permeable stone 9 .

In order to further optimize the above technical solution, the shape and size of the groove 5, the permeable stone 9 and the filter paper 22 are the same.

In order to further optimize the above technical solution, a screw channel is provided at the bottom of the groove 5, and the screw channel is divided into different heights.

In order to further optimize the above technical solution, a rubber sealing ring 8 is also arranged in the groove 5,

In order to further optimize the above-mentioned technical solution, a supplementary drainage port 4 is provided on the side of the chassis 6, which can be used to enter liquid or discharge liquid. The supplementary drainage port 4 communicates with the lowest level of the screw channel for liquid circulation.

In order to further optimize the above technical solution, the sample loading chamber 12 and the outer ring of the chassis 6 are provided with fixing screw holes 23 at equal intervals, and the fixing screws 7 pass through the fixing screw holes 23 to realize the sealed and fixed connection between the sample loading chamber 12 and the chassis 6. make it a whole.

In order to further optimize the above technical solution, a fan 13 is arranged directly above the sample chamber to accelerate the evaporation of the sample.

The utility model connects the sample chamber and the chassis with fixing screws, puts the soil sample into the sample chamber, inserts the moisture meter and the tensiometer, adjusts the height of the liquid storage bottle through the bracket to control the water head to saturate the sample, and opens the sample chamber to replenish water. Make the water in the sample chamber under the action of gravity until the water no longer flows out, close the replenishment water outlet, turn on the fan, and accelerate the evaporation of the surface of the soil sample. Using the above-mentioned experimental device, the permeability coefficient curve of the unsaturated soil can be measured by collecting the data during the evaporation process of the soil sample.

Specifically, the method for measuring the hydraulic conductivity curve of unsaturated soil by the above-mentioned experimental device for measuring the hydraulic conductivity curve of unsaturated soil is as follows:

(1) Put a permeable stone 9 with the same diameter as the groove 5 above the chassis 6, and lay a filter paper 22 with the same size as the permeable stone 9 above the permeable stone 9. The rubber sealing ring 8 is in the groove 5, and the chassis 6 and The sample loading chamber 12 is fixed by the fixing screw 7 to realize the sealing of the two and make it a whole. Put the sample to be tested into the sample chamber, insert the moisture meter 10 and the tensiometer 11, and seal it with glass glue.

(2) The weighing unit is connected to the computer 18, and the moisture meter 10 and the tensiometer 11 in the data acquisition system are connected to the computer 18 through data lines.

(3) The fan 13 is connected to the computer 18, so that the fan 13 is aimed at the upper surface of the sample chamber filled with the soil sample, so as to accelerate the evaporation of the soil sample to be tested.

(4) Connect the liquid storage bottle 1 of the water supply system to the sample chamber through the rubber tube 3, and adjust the height of the liquid storage bottle 1 through the bracket 19 to control the water head to fully saturate the sample. After the sample is saturated, disconnect the liquid storage bottle 1 from the sample chamber. For the connection of the sample chamber, cover the surface of the soil sample with a plastic film to allow the excess water in the soil sample to drain freely under the action of gravity. After the weight of the sample is stabilized, close the replenishment drain 4 of the sample chamber, uncover the plastic film, and turn on the fan 13 .

(5) Control it to read a number at a certain time interval by the acquisition program of computer 18, obtain the water content, soil matrix suction and the quality of the device at this time, thereby obtain the curve of the above-mentioned parameters, and obtain the curve of the permeability coefficient K by calculation .

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other. As for the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and for the related information, please refer to the description of the method part.

The above description of the disclosed embodiments enables those skilled in the art to realize or use the utility model. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. An experimental device for measuring an unsaturated soil permeability coefficient curve, characterized in that it comprises a weighing unit, a sample chamber, a liquid supply system and a data acquisition system; Wherein the sample chamber communicates with the liquid supply system through a rubber tube (3), the sample chamber includes a chassis (6) and a sample loading cavity (12), and the chassis (6) is arranged on the top of the weighing unit, The sample loading cavity (12) is located at the top of the chassis (6) and is fixedly connected with the chassis (6); The data acquisition system comprises a moisture meter (10), a tensiometer (11), a data collector (17) and a computer (18), and the moisture meter (10) and the tensiometer (11) are inserted into the sample loading In the sample to be measured in the chamber (12), the data collector (17) is electrically connected to the weighing unit, the moisture meter (10), and the tensiometer (11) respectively, and transmits electrical signals to The computer (18). 2. a kind of experimental device of measuring unsaturated soil permeability coefficient curve according to claim 1, is characterized in that, described weighing unit comprises upper metal plate (1401), lower metal plate (1402) and pressure sensor (15 ), the pressure sensor (15) is fixedly arranged between the upper metal plate (1401) and the lower metal plate (1402). 3. A kind of experimental device for measuring the permeability coefficient curve of unsaturated soil according to claim 2, characterized in that, said weighing unit is also provided with a balance adjustment device. 4. a kind of experimental device of measuring unsaturated soil permeability coefficient curve according to claim 1, is characterized in that, described liquid supply system comprises liquid storage bottle (1) and support (19), and described liquid storage bottle ( 1) It is arranged on the bracket (19) whose height can be adjusted, and the bottom of the liquid storage bottle (1) is provided with a liquid outlet (2). 5. a kind of experimental device of measuring unsaturated soil permeability coefficient curve according to claim 1, is characterized in that, described chassis (6) top is provided with groove (5), and is arranged in described groove (5) There are permeable stones (9) and filter paper (22), and the filter paper (22) is located on top of the permeable stones (9). 6. A kind of experimental device of measuring unsaturated soil permeability coefficient curve according to claim 5, is characterized in that, described groove (5) bottom is provided with threaded channel, and described threaded channel is set to different heights. 7. The experimental device for measuring the permeability coefficient curve of unsaturated soil according to claim 5, characterized in that, the outer ring of the groove (5) is provided with a sealing ring (8). 8. a kind of experimental device of measuring unsaturated soil permeability coefficient curve according to claim 6, is characterized in that, described chassis (6) side is provided with make-up drain (4), and described make-up drain (4) communicates with the lowest first order of the threaded channel. 9. a kind of experimental device of measuring unsaturated soil permeability coefficient curve according to claim 1, is characterized in that, described sample chamber (12) and described chassis (6) outer ring are equidistantly provided with fixing screw inserts hole (23), and the fixing screw (7) passes through the fixing screw insertion hole (23), so as to realize the sealed and fixed connection between the sample loading chamber (12) and the chassis (6). 10. The experimental device for measuring the permeability coefficient curve of unsaturated soil according to claim 1, further comprising a fan (13), the height of the fan (13) being equal to the surface of the sample chamber.