Apparatus and method for measuring salinity of interstitial water collected from soil sample

1. An apparatus for measuring salinity of interstitial water in a soil sample, comprising:

an air supplier that generates a stream of high-pressure air;

an air nozzle from which the high-pressure air, supplied from the air supplier, is ejected;

a soil-compressing tank into which the high-pressure air, ejected from the air nozzle, is introduced and that compresses a soil sample contained therein to squeeze interstitial water from the soil sample; and

a water tank that collects and stores the interstitial water drained from the soil-compressing tank and in which a salinity-measuring sensor for measuring salinity is installed to measure salinity of the interstitial water,

wherein,

in the soil-compressing tank, an upper filter assembly and a lower filter assembly are sequentially stacked and the soil sample is disposed in a gap between the upper filter assembly and the lower filter assembly.

2. The apparatus according to claim 1 , wherein the upper filter assembly and the lower filter assembly are sequentially stacked and horizontally or vertically arranged, the soil sample is stacked in the gap between the upper filter assembly and the lower filter assembly, and a middle portion of the soil sample is pushed to create a fault line by a pressure of the high-pressure air supplied through the air nozzle, causing shear stress.

3. The apparatus according to claim 1 , wherein the upper filter assembly and the lower filter assembly have a structure in which a first metal filter, a paper filter, and a second metal filer are sequentially stacked.

4. The apparatus according to claim 3 , wherein the first metal filters of the upper filter assembly and the lower filter assembly have a plurality of through-holes.

5. The apparatus according to claim 4 , wherein the first metal filter of the upper filter assembly has a through-hole-free portion facing the air nozzle in a center portion thereof.

6. The apparatus according to claim 1 , wherein the upper filter assembly and the lower filter assembly have a structure in which two metal filters are spaced by a spacer.

7. The apparatus according to claim 6 , wherein the metal filters of the pair of metal filters have holes that can be aligned, but the pair of metal filters are arranged so that the through-holes of the metal filters are not aligned with each other.

8. An apparatus for measuring salinity of interstitial water in a soil sample, comprising:

an air supplier that generates a stream of high-pressure air;

an air nozzle from which the high-pressure air, supplied from the air supplier, is ejected;

a soil-compressing tank into which the high-pressure air, ejected from the air nozzle, is introduced and that compresses a soil sample disposed in a gap formed between an upper filter assembly and a lower filter assembly, producing interstitial water; and

a water tank in which the interstitial water, drained from the soil-compressing tank, is collected and in which a salinity-measuring sensor for measuring salinity of the interstitial water is installed,

wherein,

a middle portion of the soil sample is pushed by the high-pressure air introduced into the soil-compressing tank connected to the air nozzle, creating a fault line in the soil sample, and shear stress applied to the soil sample is measured by a load cell installed on one side of the lower filter assembly.

9. An apparatus for measuring salinity of interstitial water in a soil sample, comprising:

an air supplier that generates a stream of high-pressure air;

an air nozzle from which the high-pressure air, supplied from the air supplier, is ejected;

a soil-compressing tank into which the high-pressure air, ejected from the air nozzle, is introduced and that compresses a soil sample disposed in a gap formed between an upper filter assembly equipped with a gauge and a lower filter assembly, producing interstitial water; and

a water tank in which the interstitial water, drained from the soil-compressing tank, is collected and in which a salinity-measuring sensor for measuring salinity of the interstitial water is installed,

wherein,

a distance between a wall of the soil-compressing tank and the soil sample increases with time due to the high-pressure air introduced into the soil-compressing tank connected to the air nozzle and the distance is measured by the gauge to determine consolidation of the soil sample.

10. A method for measuring salinity of interstitial water in a soil sample, comprising:

removing an upper filter assembly from a soil-compressing tank;

putting a predetermined amount of collected soil sample into the soil-compressing tank from which the upper filter assembly is removed;

stacking and pressing the upper filter assembly on and against an upper surface of the soil sample;

starting operation of an air supplier;

introducing high-pressure air to the soil-compressing tank through an air nozzle in a state in which the upper filter assembly is stacked on and pressed against the soil sample;

squeezing interstitial water contained in the soil sample using a pressure of the high-pressure air and draining the interstitial water;

collecting the drained interstitial water in a water tank;

measuring salinity of the interstitial water stored in the water tank using a salinity-measuring sensor after collection of the interstitial water is completed; and

processing data of the measured salinity of the collected interstitial water stored in the water tank.

11. The method according to claim 10 , wherein in the step of introducing the high-pressure air through the air nozzle in a state in which the upper filter assembly is stacked and pressed, a metal filter of the upper filter assembly has a through-hole.

12. The method according to claim 10 , wherein in the step of introducing the high-pressure air through the air nozzle in the state in which the upper filter assembly is stacked and pressed, two metal filters of the upper filter assembly are spaced by a spacer, and a turbulent stream of air is formed thereby.