JP4217953B2 - Test method for poorly water-permeable soil materials - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a test method for a hardly water-permeable soil material, and particularly relates to a test method for a hardly water-permeable soil material that makes it easy and quick to confirm the water permeability and gas permeability characteristics of the hardly water-permeable soil material.
[0002]
[Prior art]
When burying industrial waste or radioactive waste in the ground, it is effective to stop the water with a waste filler made of a soil material with a very low permeability coefficient. A material having a permeability coefficient of 1E-13 m / s or less is used as a soil material.
[0003]
Thus, the poorly water-permeable soil material does not show a correct water permeability when not saturated with water, and the granular bentonite high-density solidified material constituting the waste filler is contained therein. It has been found that by shaping so that the contained air becomes zero, it is possible to further improve the characteristics capable of maintaining the barrier function such as the required water shielding performance and radionuclide delay performance over a long period of time.
[0004]
However, since hardly permeable soil materials are installed around the waste buried underground, it is necessary to measure various characteristics such as permeability coefficient, diffusion coefficient, and mechanical characteristics in a state saturated with water. The permeability coefficient of the permeable soil material is 1E-8m / s to 1E-14m / s, which is very difficult to permeate. Therefore, in order to saturate the test specimen with water, high pressure water is injected into the specimen. Therefore, it is necessary to bring the water into a saturated state while gradually infiltrating water.
[0005]
That is, the dry density is 1600 kg / m ^Three Assuming that the permeability coefficient is 1E-13 m / s and the size of the specimen is 50 mmφ × 50 mmH, the air gap is about 30%, which is 30 ml. Therefore, if water is infiltrated into the specimen at a pressure of 10 atm, the amount of intrusion water is calculated as follows. It takes 87 days to saturate the specimen with a height of 50 mm. become.
[0006]
・ Q = k ・ i ・ A
= 1E-13 × 100 / 0.05 × 0.002 × 3600 × 24 × 1000000 = 0.346 ml / day
・ T = 30ml ÷ 0.346ml / day = 87 days
[0007]
For this reason, when reflecting in the facility design, it is possible to obtain material characteristics by giving a margin to the preliminary test schedule. In order to manage, since it is necessary to acquire quality test data of construction materials in a short time, a water permeability test that can be dealt with quickly is required.
[0008]
However, since the subsequent permeability test can measure each permeability coefficient by measuring the permeation flow rate for several types of injection pressure, the required time can be dealt with in several days. It is clear that it is most effective to improve the saturation process of the specimen in a short time in the water permeability test.
[0009]
And there is an air permeability test as a similar test for poorly water-permeable soil materials, but this test is also a test for grasping the characteristics of gas permeability using the hardly water-permeable soil material saturated with water. Therefore, it is effective to reduce the time required for saturation of the specimen in a short time as in the water permeability test.
[0010]
As described above, as a specimen for carrying out the water permeability / air permeability test and the mechanical test, it is necessary to gradually infiltrate while injecting high-pressure water into the hardly water-permeable soil material and to be saturated. When air is included, it is difficult to pursue characteristics that can maintain the barrier function such as the target water shielding performance and radionuclide delay performance over a long period of time. The establishment of the method was envied.
[0011]
As general water permeation and air permeation devices, those used for the test of water permeation pavement are introduced as follows, but the target specimen is a paved road, so the level of water permeation characteristics is completely different. Therefore, there is no room for consideration as a conventional example of the present invention.
[0012]
[Patent Document 1]
JP 2002-174588 A (page 3, identification code “0017” to page 4, identification code “0020” last line, FIGS. 1 and 2)
[0013]
In addition, the present inventors have already proposed a waste filler made of a soil material with a low permeability coefficient that can be used when burying industrial waste or radioactive waste in the ground, and a manufacturing apparatus thereof. (Japanese Patent Application No. 2002-173838) is still undeveloped about the water permeability and air permeability test methods for bentonite high density solidified bodies produced here, and it is hoped that a test method capable of rapid measurement will be established. It was rare.
[0014]
[Problems to be solved by the invention]
The present invention is proposed in view of the above situation, and the specimen of the hardly water-permeable soil material used in each of the water permeability or air permeability tests of the hardly water-permeable soil material is saturated while suppressing the inclusion of air. The present invention provides a method for testing a hardly water-permeable soil material that can complete the process in a short time and can quickly measure various properties in a state without containing air.
[0015]
[Means for Solving the Problems]
The method of testing a hardly water-permeable soil material according to claim 1 is a granulated body of a hardly water-permeable soil material adjusted to a moisture amount that causes a gas region after compression molding to be zero in a molded container in which air is excluded in advance. Next, create a specimen of poorly water-permeable soil material by compressing the granular material while evacuating it, and then move the molding container with the specimen inside to the test equipment and install it. , Saturation process of test piece of poorly permeable soil material while suppressing air content Can be completed in a short time, and various characteristics can be measured quickly without air permeating into the specimen.
[0016]
The test method for a hardly water-permeable soil material according to claim 2 is the test method according to claim 1, wherein the molded container is air-excluded by extruding air by injecting a water-soluble gas into the molded container. In addition to the above functions, it is easy to form an environment in which air is excluded.
[0017]
The test method of the hardly water-permeable soil material according to claim 3 is the test method according to claim 1 or 2, wherein the molded container moved to the test device is evacuated by evacuating the inner space. In addition to the above functions, air is prevented from penetrating into the specimen.
[0018]
A test method for a hardly water-permeable soil material according to a fourth aspect of the present invention is the test method according to the first or second aspect, wherein the molded container moved to the test apparatus is evacuated and compressed in the inner space. Residual air is excluded, and in addition to the above functions, the penetration of air into the specimen is prevented.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
In the method for testing a hardly water-permeable soil material according to the present invention, a molded container in which air has been excluded in advance is filled with a granular material of a hardly water-permeable soil material adjusted to a moisture amount that causes the gas region after compression molding to be zero, A specimen of a hardly water-permeable soil material is prepared by compressing and molding the granular material while evacuating it, and then the molding container with the specimen inside is moved to the testing device and installed, and the sample in the molding container is placed. It is based on testing by connecting each device of injection system and discharge system and the specified measuring instrument to the specimen, and extruding air by injecting water-soluble gas into the molded container and testing it. The molding container moved to the apparatus is characterized by eliminating residual air by evacuation of the inner space.
DESCRIPTION OF EMBODIMENTS Embodiments relating to a test method for hardly water-permeable soil materials according to the present invention will be described below in detail with reference to the drawings.
[0022]
FIG. 1 shows a process for producing a specimen for a water permeability test, showing a process (a) of filling a molding container with granular material of a hardly water-permeable soil material and a process (b) of molding as a test specimen. Yes.
[0023]
In the figure, 1 is a granular material for forming a specimen, which is a mixture of a material containing smectite, such as commercially available bentonite, and an aggregate, etc., or a poorly permeable soil material having a low permeability coefficient such as clay. Made of wood, water and air.
[0024]
The water content ratio of the granular material 1 is kneaded while the gas region of the saturated specimen is adjusted to an appropriate value that is exactly zero when the granular material is press-molded to a target density. The target dry density is, for example, 1600 kg / m ^Three In this case, the soil particle density is ρs = 2.743 g / cm. ^Three Then, the water content is 26.0%.
[0025]
Reference numeral 2 denotes a specimen color for filling the granular material, which is disposed between the bottom lid 3 and the compression cylinder 4. The specimen collar 2 is used to form a specimen. The granular material 1 is charged. However, in the conventional specimen pressing process, since a water-soluble gas such as air or carbon dioxide gas is confined in the granular material 1, a desired saturated specimen cannot be produced.
[0026]
However, in the present embodiment, as in the step (a) in which the granular material is filled in the molding container, the tube connected to the bottom lid 3 and the vacuum pump in order to evacuate the specimen collar 2 and the compression cylinder 4. 6 is installed in advance, and the space into which the granular material 1 is put is evacuated before press molding, or the water is replaced with water-soluble gas in advance to remove the disturbing air in advance.
[0027]
That is, in the conventional method, since a gas that is not water-soluble, such as air, is not completely evacuated, a very small amount of air remains in the granular material and water, so that a completely saturated specimen is produced. Although it was difficult, in the case of the present embodiment, a water-soluble gas such as carbon dioxide gas is filled from the injection pipe 5 and at the same time, air components are sucked from the tube 6 provided on the bottom lid 3 and removed in advance. Thus, the intermediate portion between the specimen color 2 and the compression cylinder 4 is configured to be filled with water-soluble gas such as carbon dioxide gas instead of air.
[0028]
Accordingly, the granular material 1 is loaded in a state in which unnecessary air permeation is blocked in the specimen collar 2 and the compression cylinder 4 so that only a very minute amount of air remains. It will be.
[0029]
Further, in the step of FIG. 1B for molding as a specimen, a pressing piston 7 is loaded in the compression cylinder 4 of the specimen collar 2.
[0030]
At this time, the inside of the specimen collar 2 and the compression cylinder 4 is shut off from the outside air, and the tube 6 of the bottom lid 3 is evacuated by connecting a vacuum pump (not shown). Therefore, only the granular material 1, water, dilute carbon dioxide gas, and ultra-diluted air exist inside the collar 2 for the specimen and the compression cylinder 4. Thus, the desired pressure of the specimen 8 in which the gas region becomes zero is compression-molded inside the collar 2 for the specimen by the press pressure action on the piston 7 continuously performed.
[0031]
Therefore, the test molding container 9 removed from the bottom lid 3 and the compression cylinder 4 is composed of the specimen collar 2 and the specimen 8 filled therein. The specimen 8 is composed of the granular body 1, water, a small amount of carbon dioxide gas, and an extremely small amount of air by being press-molded to a predetermined density. However, since the carbon dioxide gas confined after the compression molding is finally dissolved in the surrounding pore water, the specimen 8 inside the specimen collar 2 finally leaves only a very small amount of air. It will be formed as a specimen saturated with water.
[0032]
FIG. 2 shows a microscopic simulation of the state of change of the specimen that changes in the process of FIG.
[0033]
Fig. 2 (a) shows that when the moisture content of the granular material reaches the target density, it is adjusted to an appropriate value so that the gas region of the saturated specimen is exactly zero. In this state, the granular material 1 is kneaded while being basically composed of particles 10, water 11 and air 12.
[0034]
FIG. 2B shows the state of the granular body 1 when the granular body 1 under the state where unnecessary air permeation is blocked is filled in the specimen collar 2 and the compression cylinder 4. The specimen collar 2 and the compression cylinder 4 are replaced with air and carbon dioxide by supplying carbon dioxide and evacuating. The granular material 1 at this stage is composed of particles 10 and compressed water. 11 and carbon dioxide gas 13, and the amount of air 12 is eliminated, thereby reducing the amount.
[0035]
FIG. 2 (c) shows the state of the specimen 8 in the stage of compression and evacuation of the piston 7 continuing with the specimen collar 2 and the compression cylinder 4. The specimen 8 is composed of particles 10, water 11 having a predetermined water content ratio, a minute amount of air 12, and a minute amount of carbon dioxide gas 13.
[0036]
FIG. 2D shows the state of the specimen 8 in the final stage. The carbon dioxide gas 13 dissolves in the surrounding pore water, so that the specimen 8 is composed of particles 10, water 11 having a predetermined moisture content, and an extremely small amount of air 12.
[0037]
As described above, there is a possibility that air remains in the specimen 8, but these ultra-trace air 12 cannot be an amount that hinders the trend of permeated water flowing in the specimen 8. .
[0038]
Next, a test method using a specimen made of the hardly water-permeable soil material will be described.
[0039]
FIG. 3 is an embodiment showing test steps in the test method for hardly water-permeable soil material of the present invention.
The test method for a hardly water-permeable soil material according to the present invention is characterized in that the specimen color used when preparing the specimen is directly mounted as a test molding container in the test apparatus. It is configured so that air can be prevented from entering between the molding container.
[0040]
Fig.3 (a) has shown as a schematic diagram the arrangement | positioning state of the molding container for a test in a test apparatus, the injection | pouring apparatus of water, a discharge system apparatus, and a measurement instrument.
In the present embodiment, the specimen color 2 used when creating the specimen 8 as the test molding container 9 in the test apparatus 15 is used as it is, and the test molding container 9 is used as the upper and lower lids of the test apparatus 15. It is mounted between the plates 16, 16 '. A vacuum pump (not shown) is connected to each of the upper and lower cover plates 16 and 16 ′ of the test apparatus 15 through hollow pipes 17 and 17 and open / close valves 18, 18 and 18 ′ and 18 ′. Each intermediate portion 17 is connected via open / close valves 21, 22 of a water storage tank 19 that stores deaerated water in advance and open / close valves 21 ′, 22 ′ of a water collection tank 20.
[0041]
The test device 15 is connected to the upper and lower hollow pipes 17 after connecting the test molded container 9 to close the open / close valves 21 and 22 of the water storage tank 19 and the open / close valves 21 ′ and 22 ′ of the water collection tank 20. The vacuum pump is operated to evacuate the inside of the hollow pipe 17 of the test molded container 9, the water injection system device, and the discharge system device.
[0042]
As a result, the specimen 8 in the specimen collar 2 further carefully excludes air that may be infiltrated during the transition, and as a result, air is mixed in the permeability test system. Therefore, the water permeability in the test system can be measured through the complete specimen 8 saturated with water having a predetermined water content ratio.
[0043]
As a method for further completely preventing air from remaining in the water permeation test system, it is possible to evacuate after replacing the interior of the system with a water-soluble gas such as carbon dioxide gas in advance.
[0044]
FIG. 3B shows a schematic diagram of a process for introducing deaerated water into the water permeation test system by switching the open / close valve in the test apparatus.
In this step, the hollow pipe 17 on the side to which the vacuum pump is connected is closed by switching the opening / closing valve 18 ′, and the opening / closing valves 21, 22 of the water storage tank 19 storing degassed water By switching the open / close valves 21 ′ and 22 ′ of the water collection tank 20 and the open / close valve 18 of the hollow pipe 17 to open, a water flow state in which the water storage tank 19 and the water collection tank 20 communicate with each other is formed.
[0045]
Next, the test apparatus 15 introduces the degassed water into the water collecting tank 20 while infiltrating the test molded container 9 by the injection of the water injection pressure control gas into the water storage tank 19. Since the inside of the hollow pipe 17 of the system device and the discharge system device is formed in a vacuum state as described above, the degassed water stored in the water storage tank 19 penetrates the sample 8 without difficulty and is saturated. Forming a state.
[0046]
As described above, in the method for testing a hardly water-permeable soil material according to the present invention, the specimen color used when creating the specimen as a test molding container of the testing apparatus is used as it is, and from the outside of the testing apparatus. By easily preventing air from penetrating into the specimen, the time required for the saturation process is reduced to almost zero without requiring a long time as in the prior art, and the water permeability test can be started immediately. .
[0047]
FIG. 4 is a schematic diagram showing an embodiment for accurately measuring an extremely small amount of water permeability in the test method of the present invention.
[0048]
In the present embodiment, the water collection tank 20 is filled with deaerated water by the above-described pretreatment, and the water permeability is measured after that.
[0049]
The measurement is carried out by injecting degassed water from the water storage tank 19 into the specimen 8 by injecting a constant water injection pressure control gas into the water tank 19, and collecting the degassed water discharged from the specimen 8. After being received by the tank 20, the meniscus moving speed indicated by the discharged water is measured with respect to the discharged water pushed out from the transparent tube 23 with a small inner diameter of about 2 mm connected to the outlet side of the water collecting tank 20. It is done by doing.
[0050]
Since the water permeability measured in the test is about 0.346 ml / day as in the above-described calculation example, or about 1/10 of this flow rate, it is necessary to consider ultra-trace measurement. However, even if a tube having an inner diameter of 2 mm is employed as in the present embodiment, the water permeation amount corresponding to the moving amount of the meniscus is 10 mm / day is 0.1 × 0.1 × 3.14 × 1 = 0. Since it is 03 ml / day, sufficient resolution can be exhibited.
[0051]
In the test of the hardly water-permeable soil material, the permeability coefficient (ml / s) is measured from the movement speed of the meniscus of the discharged water, and the small inner diameter tube 23 used for the above-described measurement. Can be directly connected to the open / close valve 18 of the hollow pipe 17 instead of the outlet side of the water collection tank 20.
[0052]
Furthermore, the measurement is carried out by connecting a water collection bag (not shown) to the tip of the minute inner diameter tube 23, and using a commercially available weighing scale having a resolution of 0.001 g, It is also possible to measure the water transmission rate (ml / s) by measuring the weight increase once a day.
[0053]
As described above, in the method for testing a hardly water-permeable soil material according to the present invention, the test specimen color used when preparing the specimen is directly used as a test molding container so that air penetrates into the specimen. Blocking the time required for the saturation process by increasing the time required for the saturation process by configuring the arrangement of the test molding container, injection system device, discharge system device and measuring instrument in the test device while preventing air penetration. It is possible to conduct a water permeability test without any need.
[0054]
The test method of the hardly water-permeable soil material according to the present invention is not limited to the vacuuming of the inner space of the molding container as in the above embodiment, but the vacuum of the inner space of the molding container moved to the test apparatus is not limited. It is also possible to eliminate residual air by pulling and further compression molding of the specimen.
[0055]
In the following, the present embodiment will be described in detail based on the schematic diagram of FIG. 5, but the same parts as those in the above embodiment are indicated by the same reference numerals.
[0056]
Fig.5 (a) has shown as a schematic diagram the arrangement | positioning state of the molding container for a test in a test apparatus, the injection | pouring apparatus of water, a discharge system apparatus, and a measurement instrument.
In the present embodiment, the specimen collar 2, the compression cylinder 4, and the piston 7 that are used when the specimen 8 is created as the test molding container 26 in the testing apparatus 25 are used as they are, and the specimen 8 is vacuumed. While performing the pulling, the compression is also performed at the same time.
[0057]
In the present embodiment, the test molding container 26 is mounted on the bottom plate 27 of the test apparatus 25. A vacuum pump (not shown) is connected to the bottom plate 27 and the piston 7 of the test apparatus 15 through the hollow pipes 17 and 17 and the open / close valves 18, 18 and 18 ′, 18 ′, as in the above embodiment. In addition, a water storage tank 19 and a water collection tank 20 for storing deaerated water in advance are connected to each intermediate portion of the hollow pipe 17 via open / close valves 21 and 22 and open / close valves 21 ′ and 22 ′. Yes.
[0058]
The test apparatus 25 connects the test molded container 26 to close the open / close valves 21 and 22 of the water storage tank 19 and the open / close valves 21 ′ and 22 ′ of the water collection tank 20, and then uses the piston 7 to close the specimen 8. While continuing the compression molding, the vacuum pumps connected to the hollow pipes 17 are operated to evacuate the hollow pipes 17 of the test molding container 26, the water injection system device, and the discharge system device. Yes.
[0059]
As a result, the specimen 8 in the test molding container 26 further excludes air that may permeate during the transition, and as a result, air may be mixed into the water permeability test system. Therefore, the water permeability in the test system can be measured through the complete specimen 8 saturated with water having a predetermined water content ratio.
[0060]
At this time, as a method for further completely preventing air from remaining in the water permeation test system, the inside of the system is previously replaced with a water-soluble gas such as carbon dioxide gas, and vacuuming is performed in the same manner as in the above embodiment. .
[0061]
FIG. 5B shows a schematic diagram of a process for introducing deaerated water into the water permeation test system by switching the open / close valve in the test apparatus.
In this step, the hollow pipe 17 on the side to which the vacuum pump is connected is closed by switching the opening / closing valve 18 ′, and the opening / closing valves 21, 22 of the water storage tank 19 storing degassed water By switching the open / close valves 21 ′ and 22 ′ of the water collection tank 20 and the open / close valve 18 of the hollow pipe 17 to open, a water flow state in which the water storage tank 19 and the water collection tank 20 communicate with each other is formed.
[0062]
The test device 25 guides water degassed by injection of a water injection pressure control gas into the water storage tank 19 and infiltrates the test molding vessel 26 to the water collection tank 20. Since the hollow pipe 17 of the system apparatus is formed in a vacuum state, the degassed water stored in the water storage tank 19 penetrates the specimen 8 without difficulty and forms a saturated state.
[0063]
Therefore, also in the case of this embodiment, the time required for the saturation process is made almost zero without requiring a long time as in the prior art by preventing the air from outside the test apparatus from penetrating into the specimen. The water permeability test can be started immediately, and the subsequent test is the same as in the above embodiment.
[0064]
Furthermore, the situation where the gas region such as air becomes zero in a specimen made of a hardly water-permeable soil material will be described.
[0065]
FIG. 6 shows the relationship between the compressive stress and the dry density. The pressing operation of the specimen is an experimental result of pressing at a speed of about 0.65 mm / min using a 2000 kN Amsler loading device. The relationship between the press pressure and the dry density is plotted by obtaining the dry density of the hardly water-permeable soil material from the measured value of the specimen height during the press.
[0066]
As shown in the figure, in this experiment, the reaction force suddenly rises when the dry density approaches 1.6, but as is apparent from this phenomenon, the gas region such as air is zero at this point. From this, it is possible to know that the transition to the rigid behavior of clay particles, pore water or metal of the press mold is made, and the gas region such as air in the hardly permeable soil material described above can be made zero. It has been shown that potential can be established.
[0067]
Similarly, FIG. 7 shows actual measurement data obtained by measuring a very small amount of water permeation by the test method of the present invention shown in FIG. 4 while using a specimen of a hardly water-permeable soil material in a molded container compression molded according to the present invention. It is.
[0068]
In this test, a dry density of 1600 kg / m as a hardly water-permeable soil material ^Three Using a commercially available bentonite with a saturation degree of 98.8%, the dimensions of the specimen are 50 mmφ x 20 mmH, and deaerated water is injected into the specimen at a pressure of 0.4 MPa. is doing.
[0069]
In the graph of FIG. 7, the horizontal axis represents time (seconds) and the vertical axis represents the cumulative water permeability (ml), and the water permeability was measured from the meniscus movement amount on the drainage side 23 in FIG. 4 in this test. It is the actual value which plotted the value.
[0070]
As shown in the figure, although the water permeability cannot be confirmed in the first two days, the value that can be sufficiently observed from the third day is clarified. Incidentally, the permeability coefficient calculated from the permeability value of the third day to the eighth day is 8.4E-14 m / s, and the long-term permeability coefficient from the third day to the 22nd day is 8.7E-14 m. / S.
[0071]
As described above, the present invention has been described in detail on the basis of the embodiment. However, the method for testing a hardly water-permeable soil material according to the present invention is not limited to the above-described embodiment, and in the hardly water-permeable soil material. It is possible to deal with the air permeability test in the same manner, and to make other configurations specifically regarding the test molded container, the water injection system device, the discharge system device, the measuring instrument, etc., the above-mentioned purpose of the present invention It goes without saying that various modifications are possible without departing from the scope of the present invention.
[0072]
【The invention's effect】
The test method for a poorly water-permeable soil material according to claim 1 is a method in which a molded container in which air is excluded in advance is filled with a granular material of a hardly water-permeable soil material adjusted to a moisture amount that causes a gas region after compression molding to be zero. Then, a specimen of a hardly water-permeable soil material is created by compressing and molding the granular material while evacuating, and then the molding container with the specimen inside is moved to the test apparatus and installed, and the molding container Since the injection system and the discharge system and the specified measuring instruments are connected to the specimen in the test, the saturation process is completed in a short time while maintaining the air content of the specimen of the hardly permeable soil material. In addition, there is an effect that various characteristics can be quickly measured without air permeating into the specimen.
[0073]
The test method of the hardly water-permeable soil material according to claim 2 is the test method according to claim 1, wherein air is extruded by injecting a water-soluble gas into the molding container in order to eliminate air from the molding container. In addition to the above-described effects, it has the effect of facilitating the formation of an environment in which air is excluded.
[0074]
The test method for a hardly water-permeable soil material according to claim 3 is the test method according to claim 1 or 2, wherein the molded container moved to the test apparatus is evacuated from the inner space to remove residual air. Therefore, in addition to the above-described effects, the effect of preventing the penetration of air into the specimen is achieved.
[0075]
The test method of the hardly water-permeable soil material according to claim 4 is the test method according to claim 1 or 2, wherein the molding container moved to the test apparatus is evacuated and compressed to form residual air. Since it is characterized by eliminating, in addition to the above effects, the effect of preventing the penetration of air into the specimen is achieved.
[Brief description of the drawings]
FIG. 1 is an embodiment showing a manufacturing process of a specimen in a test method for a hardly water-permeable soil material of the present invention.
FIG. 2 is a microscopic simulation diagram showing the state of transformation of a specimen that changes during the manufacturing process.
FIG. 3 is a schematic diagram showing a state in which a test molded container, a water injection system apparatus, a discharge system apparatus, and a measuring instrument are arranged in the test apparatus.
FIG. 4 is a schematic diagram showing an embodiment of measurement in the test method of the present invention.
FIG. 5 is a schematic view showing another embodiment relating to a test method for a hardly water-permeable soil material in the present invention.
[Fig. 6] Results of experiments showing the relationship between compressive stress and dry density in poorly permeable soil materials
[Fig. 7] Actual measured data of water permeability in the test method for hardly permeable soil materials in the present invention.
[Explanation of symbols]
1 powder, 2 color for specimen, 3 bottom lid, 4 compression cylinder,
5 injection pipe, 6 tube, 7 piston, 8 specimen,
9 Test container, 10 particles, 11 water, 12 air,
13 carbon dioxide, 15, 25 test equipment, 16, 16 'upper and lower cover plates,
17 hollow pipe, 18, 18 'open / close valve, 19 water storage tank,
20 water collection tank, 21, 21 ', 22, 22' opening and closing valve,
23 tubes, 26 molded containers for testing, 27 bottom plate,

Claims (4)

  By filling the molding container in which air is excluded in advance with a granular material of a hardly water-permeable soil material adjusted to a moisture content that eliminates the gas region after compression molding, and then compressing the granular material while vacuuming Create a specimen of poorly permeable soil material, and then move and set the molding container with the specimen built in to the testing device, and put each of the injection system and the discharge system on the specimen in the molding container. And a method for testing a hardly water-permeable soil material to be tested by connecting a predetermined measuring instrument.   2. The method for testing a hardly water-permeable soil material according to claim 1, wherein the air is excluded from the molded container by extruding air by injecting a water-soluble gas into the molded container.   3. The method for testing a hardly water-permeable soil material according to claim 1 or 2, wherein the molded container moved to the test apparatus is free of residual air by evacuation of the inner space.   The method for testing a hardly water-permeable soil material according to claim 1 or 2, wherein the molded container moved to the test apparatus is free of residual air by evacuation of the inner space and compression molding.

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