JP3120674B2 - Permeability test equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for testing water permeability and air permeability, and more specifically, for example, to grasp airtightness of compressed air storage rock, prevent leakage of oil and gas storage rock, and grasp airtightness.
The present invention relates to a permeability test apparatus used for evaluation of permeability of a pneumatic tunnel in civil engineering construction.

[0002]

2. Description of the Related Art As a radioactive waste disposal facility for stably storing radioactive waste generated in a nuclear power business without leaking radioactivity to the outside, for example,
A radioactive waste is sealed and stored in a groundwater tank having a configuration as shown in FIG. That is, the underground water tank body 100 is made
Are covered in order from the inside with a highly permeable mortar layer 102, a porous concrete layer 103, a concrete skeleton 104, a buffer layer 105 and a bentonite mixed soil layer 106. The underground water tank body 100 is embedded in a hole formed by hollowing out rock, and a sufficient cover is applied to the upper part thereof. The bentonite-mixed earth tank 103 is a mixture of earth and sand of about 85% by weight and about 15% of bentonite, and is formed by adding water and kneading. By having a water content of about 14%, it has a hardness of about gypsum.

[0003] The underground water tank body for enclosing radioactive waste as described above needs to have a certain degree of air permeability because it is necessary to release gas generated from radioactive waste to the outside. Since such underground water tanks require strict reliability, it is necessary to accurately grasp the water permeability and air permeability. However, since the bentonite-mixed earth tank used for this underground water tank body is mainly made of natural materials and has swelling properties, it is necessary to accurately calculate the water permeability and air permeability in the desk calculation. It is impossible to calculate, and it is necessary to confirm the self-healing property of the water permeation by repeating water permeation and air permeation alternately several times.

[0004] Conventionally, the measurement of water permeability and air permeability of a sample such as soil or rock has conventionally been carried out by sandwiching a sample to be measured in a sealed container (air permeable container) by sandwiching the sample from above and below with a porous support. The side surface of the measurement sample is surrounded by a non-air-permeable, water-impermeable elastic member such as a rubber membrane. Water is allowed to pass through the flow path communicating with the bottom side of the sealed container, and water or gas is sent from the flow path communicating with the bottom side of the sealed container, and the water flows out through the flow path connected to the top side of the sealed container through the sample to be measured. Or by measuring the amount of gas. Then, based on the measured values, the air permeability and the water permeability are obtained based on the following equations (1) and (2).

[0005]

(Equation 1)

[0006]

(Equation 2)

FIG. 6 is a cross-sectional view showing a main part of a gas permeable container in a conventional gas permeable test apparatus used for measuring the gas permeable coefficient as described above. As shown in FIG.
Is mounted on a first pellet style 54 and a first porous disc-shaped member 53 placed on the air-permeable container main body 50, and the side surface thereof is covered with a rubber film 52.
In addition, a connection pipe 55 that forms a flow path communicating with a water supply source and a gas supply source (neither is shown) is hermetically inserted through an O-ring at the center of the air-permeable container main body 50. The first pellet style 54 communicates with the flow path of the connecting pipe 55 on the lower end side and has the diameter of the first porous disc-shaped member 53 or the sample 51 to be measured placed on the upper end side. It has a flow path with a substantially T-shaped cross section, which is enlarged so that water or gas can be supplied evenly in the entire direction.

Conventionally, when measuring the water permeability coefficient using such a water permeability test apparatus, water is first sent from a water supply source into the air permeable container body 50, and the sample 51 to be measured is passed through the water source. After saturation, the coefficient of water permeability was measured.
To measure the air permeability coefficient.

However, a water permeability test is performed by sending water as described above, and a gas permeability test using gas is performed while water remains in the first pellet style 54 and the first porous plate-like member 53. , Accurate air permeability test cannot be performed. Therefore, the air permeability test was performed after the water staying in the first pellet style 54 and the first porous disk-shaped member 53 was released. This required a long lasting period of several tens of days.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide an improved water and air permeability test apparatus which shortens the time required for measuring the air permeability from the measurement of the water permeability and simplifies the measurement operation. The purpose is to:

[0011]

Means for Solving the Problems To achieve the above object, a water permeability test apparatus according to the present invention measures a water permeability by passing water, and then sends a gas to measure the gas permeability. First, water staying in the first porous disc-shaped member and the first pellet style (hereinafter, referred to as drain water).
Is removed without sending it to the sample to be measured, and gas can be sent directly to the lower surface of the sample to be measured.

That is, the water and gas permeability test apparatus according to the present invention is provided in a sealed container having a water and gas supply system connected to one end and a water and gas measurement system connected to the other end opposed thereto. In a water-permeable and air-permeable test device in which a sample to be measured is sandwiched by having a fluid flow path forming member and a porous support in front and behind, respectively, after a water-permeability test is completed, the device is located on the water and gas supply system side. A drain discharge mechanism is provided for discharging a fluid remaining in the flow path of the fluid flow path forming member and the porous support.

It is preferable that the drain discharge mechanism has a means for blowing gas into a flow path of a fluid flow path forming member located on the water and gas supply system side.

[0014]

As described above, in the water and gas permeability test apparatus according to the present invention, the fluid remaining in the flow path of the fluid flow path forming member located on the side of the water and gas supply system and in the porous support is separated from the water and gas. Since a drain discharge mechanism is provided to discharge the supply system, drain water can be drained out of the system in a short time after measuring the water permeability, and sent from the water and gas supply system when measuring the air permeability. The incoming gas can be supplied directly to the lower surface of the sample to be measured, and the time required from the measurement of the water permeability to the measurement of the air permeability can be greatly reduced.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to embodiments. FIG. 1 is an apparatus circuit diagram schematically showing the overall configuration of a water and air permeability test apparatus according to one embodiment of the present invention, and FIG. 2 is a cross-sectional view showing the main configuration of the water and air permeability test apparatus according to the present invention. FIG. 3 is a sectional view taken along line III-III in FIG.

As shown in FIG. 1 and FIG. 2, the water permeability test apparatus of this embodiment is a three-axis water permeability test apparatus for measuring the permeability coefficient of soil, rocks, etc. A gas permeable container 2 for accommodating the sample 1, a water vent portion A for allowing water to flow and vent to the sample 1 contained in the gas permeable container 2, and a gas permeable container A A measuring unit B for measuring the amount of water and gas passing through the measured sample 1, and a side pressure introducing unit C for applying a predetermined side pressure to the side surface of the sample 1 stored in the gas permeable container 2. And a drain water discharge gas introduction part D for supplying gas for drain water discharge in the gas permeable container 2.

The gas permeable container 2 has a gas permeable container body 3 having an open upper end, and a gas permeable container lid 4 for closing the upper end opening of the gas permeable container body 2. The joint between the air container body 3 and the lid 4 is fixed by bolts 5 in order to maintain the airtightness and liquid tightness of the surrounding space. In the gas permeable container 2, a first pellet style 6, a first porous disk-shaped member 7, a sample 1 to be measured, and a (2) A porous disk-shaped member 8 and a second pellet style 9 forming a flow path having a substantially inverted T-shaped cross section are stacked and mounted in order, and the side surfaces of these stacked bodies are covered with a rubber film 10. ing.

The bottom center of the air-permeable container body 3
Has a line L of the water-flow ventilation section A. _a1And L_a2Communicate with
The connecting pipe 12 that forms the flowing channel is air-tight through an O-ring or the like.
It is inserted tightly. The flow path of the first pellet style 6
Communicates with the flow path of the connection pipe 12 on the lower end side,
At the upper end side, the first hole placed on the upper end
The disk-shaped member 7 or the sample 1 to be measured
Funnel so that water or gas can be supplied
The cross-section is enlarged to have a substantially T-shaped cross section. In addition,
This enlarged portion does not necessarily have to be tapered,
And the like. On the other hand, the air-permeable container lid
4 through the opening provided at the center of the second
The upper end of the tile 9 protrudes to the outside.
Even in this case, airtightness is maintained by an O-ring or the like.

In the air permeable container 2, a water tank of the side pressure introducing portion C is provided in a gap between the laminated body surrounded by the rubber film 10 and the inner peripheral surface of the air permeable container main body 3. 11
From the void portion to the communication with the line L _c1 predetermined lateral pressure meets the distilled water supplied to the DUT via, for example, applying a pressure of about 0.1~10.0kgf / cm ^2, the lateral Is cut off, and only the up-down direction is made possible.

Further, in the gas permeable container 2, a drain water discharge gas supply pipe 15 connected to the line L _{d 1} of the drain water discharge gas inlet D is formed through the bottom surface of the gas permeable container body 3. As shown in FIGS. 2 and 3, it is connected to a gas blowing passage 15a formed in the first pellet style 6.
The gas outlet passage 15a communicates with the gas supply pipe 15 through the annular groove 16, and the outlet is opened in the middle of the thickness of the first porous disk-shaped member 7.

As shown in FIG. 1, the measurement of the hydraulic conductivity
As described above, the sample 1 to be measured is placed in
In a state where pressure is applied, the compressor of
13, a predetermined pressure, for example, 0.1 to 10.0 kgf / cm
^Two Line L of compressed air _a5Through the lower air tiger
And then extruded by compressed air
To the line L_c2And air through the connecting pipe 12
This is performed by feeding into the container 2. Air permeable container
2, the water that has passed through the sample to be measured
It is guided to the outside of the air permeable container through the flow path of the tile 6, and this
Line of the measuring section B communicating with the flow path of the second pellet style 6
L_b1Through the upper air trap 17. Transparent
When measuring the water coefficient, the upper air trap 17
Water is completely filled, and the same amount of water as
Inn L_b2Through the burette and into the sealed burette 18
Sent in. Therefore, measurement in a closed burette
The water permeability is calculated from the water level difference from the start, and this value is
The water permeability is determined by introducing the above equation (2).

After measuring the water permeability in this way, the measurement of the air permeability is then started. In the test apparatus of the present invention, first, after the measurement of the water permeability, the drain gas discharge section D Compressed air and / or gas flows through the line L _d1 of the drain water discharge gas supply pipe 15.
Through the outlet of the gas outlet passage 15a through the first
It is led out into the porous disk-shaped member 7. Most of the drain water remaining in the first porous disc-shaped member 7 and the first pellet style is directed downward by the introduced air or gas with low airflow resistance, passes through the connecting pipe 12 and passes through the air permeable container 2.
It flows out. A drain line (not shown) is separately provided in the mounting block 19 that controls the connection between the connection pipe 12 and the on-off valves provided at the respective _ends of the lines _La1 and _La2. It is discharged out of the system. Of course, a drain in the opposite direction is also possible.

When drain water is discharged out of the system,
Line compressed air from compressor 13 in water vent A
L_a4To the accumulator 20 via the
L _a3Helium gas and hydrogen from gas cylinder 21 through
A predetermined gas such as a gas is flowed, and the accumulator 20
Predetermined pressure, for example, 0.1 to 10.0 kgf / cm^Two degree
Gas and compressed air of pressure L_a1and
It is sent into the air permeable container 2 via the connection pipe 12. Air permeability
In the container 2, the compressed air passing through the sample to be measured and
And gas are passed through the flow path of the second pellet
Guided to the outside, communicating with the flow path of this second pellet style 6
Line L of the measuring unit B_b1Through the upper air trap
It is sent to 17. Compressed air in upper air trap 17
And when gas is introduced, it is stored in the air trap 17.
The water that has been removed depends on the amount of inflow of compressed air and gas.
And line L_b2Leaked through the closed burette 1
It is sent to 8. Therefore, in a closed burette
The air permeability is determined from the water level difference from the start of the measurement.
The air permeability coefficient is determined by introducing the value into the above equation (1).
You.

Further, by repeating the measurement of the water permeability and the gas permeability several times as described above, the self-healing property of the sample with respect to the water permeability is confirmed. FIG. 4 is a graph showing an example of the results of measuring the permeability and permeability of a bentonite-mixed soil tank used for a groundwater tank body for radioactive waste using the permeability and permeability test apparatus according to the present invention as described above. It is.
As shown in the figure, it is apparent that the time required for such a measurement is greatly shortened and the efficiency is high when the water permeability test apparatus according to the present invention is used.

The configuration of the water-permeable and air-permeable test apparatus of the present invention is not limited to the configuration shown in the above-described embodiment, and the drain discharge mechanism also functions as a fluid flow device located on the water and gas supply system side. Any structure may be used as long as the drain water remaining in the flow path of the path forming member and the porous support is discharged to the water and gas supply system side.

[0026]

As described above, in measuring the permeability coefficient of a sample such as soil and rock by using the permeability test apparatus of the present invention, it is necessary to measure the permeability coefficient from the measurement of the permeability coefficient. The measurement time can be shortened and the measurement operation can be simplified.

[Brief description of the drawings]

FIG. 1 is an apparatus configuration diagram schematically showing the overall configuration of an apparatus for testing water permeability and air permeability according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a configuration of a main part of the water / air permeability test apparatus of the embodiment.

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is a graph showing a change in water permeability measured using a water permeability test apparatus according to the present invention.

FIG. 5 is a cross-sectional view showing a structure of a groundwater tank for storing radioactive waste.

FIG. 6 is a cross-sectional view showing a configuration of a main part of an example of a conventional water permeability and air permeability test apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Sample to be measured 2 ... Air permeable container 3 ... Air permeable container main body 4 ... Air permeable container lid 6 ... 1st Pellet style 7 ... 1st porous disk-shaped member 8 ... 2nd porous disk-shaped member 9 ... Second Pellet Style 10 Rubber Film 11 Water Tank 12 Connection Pipe 13 Compressor 14 Lower Air Trap 15 Gas Drain Water Discharge Gas Supply Pipe 15 a Gas Passage Channel 16 Annular Groove 17 Upper Air Trap 18 Closed buret 20 ... Accumulator 21 ... Gas cylinder 100 ... Groundwater tank body 103 ... Bentonite mixed earthen tank

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01N 15/08 G01N 33/24

Claims (2)

(57) [Claims] 1. A fluid flow path forming member and a porous support in a sealed container having one end connected to a water and gas supply system and the other end opposed to the water and gas measurement system. In the water permeability test apparatus in which the sample to be measured is sandwiched by being present before and after each, after the water permeability test is completed, the inside of the flow path and the pores of the fluid flow path forming member located on the water and gas supply system side A water permeation test apparatus comprising a drain discharge mechanism for discharging a fluid remaining in a porous support. 2. The water and gas permeability test apparatus according to claim 1, wherein the drain discharge mechanism has a means for blowing a gas into a flow path of a fluid flow path forming member located on a water and gas supply system side.