JP2018145599A - Sampling method of soil sample and sampling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sampling method of soil samples for quickly lifting frozen soil without cutting work (coring) of the circumference of a frozen soil sample (frozen soil column), and a sampling device.SOLUTION: A sampling method of soil samples comprises steps of: inserting a freezing pipe into soil for collecting soil samples; freezing the soil samples by cooling the freezing pipe inserted in the freezing pipe insertion step and freezing the soil samples around the freezing pipe in a roughly reverse frustum shape around the axis of the freezing pipe; and collecting the soil samples by drawing out the freezing pipe together with the frozen soil samples from the ground. The collecting step of the soil samples is performed without coring the periphery of the frozen soil samples.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sampling method and a sampling device for a ground sample for collecting ground physical property information such as sand ground in the original ground.

  Ground freezing sampling freezes the ground and freezes the pore water so that the ground is not disturbed during sampling or transportation, and solidifies the soil particles. Technology development has been underway. Typical examples are shown below.

  Patent Document 1 drills a large diameter up to the upper surface of the freezing sampling depth, drills a small diameter from the center of the hole, inserts a frozen pipe into the hole, and insulates the upper part of the large diameter boring hole to the upper part. Are connected, and an injection pipe is inserted thereinto, a refrigerant is injected from the upper part, discharged from the lower end, rises while exchanging heat in the freezing pipe, and freezes the ground. It is more economical than conventional methods because it is a large-diameter core tube that cuts frozen soil into a cylindrical shape and lifts it together with the freezing tube.

  In Patent Documents 2 and 3, a frozen outer tube is inserted into the borehole, and a frozen inner tube that has been heat-insulated is inserted above the frozen section to freeze the sampling section, and close to the frozen hole from the ground. A boring hole is provided up to the top of the frozen soil, and the core is collected by coring the frozen soil. It is economical because only a necessary number of cores are collected from the frozen soil pillar.

  According to Patent Document 4, by setting a freezing hole and a plurality of sampling guide tubes in a heat-insulated steel pipe, heat loss is small and marginal separation such as hole bending when individually drilled is unnecessary. It is characterized by being able to collect good quality samples from frozen soil with a smaller diameter.

  In Patent Document 5, in order to eliminate ground disturbance due to freezing hole boring, the ground is cut with the tip of the tip while rotating the freezing tube with a spiral wing coated with a lubricant without boring. Insert the ground into the ground while removing the cutting soil upward. A cryogenic fluid is created by supplying a cryogenic fluid from the top of the injection pipe in the freezing pipe and discharging it from the tip to ascend the freezing pipe. Since the frozen soil is cut into a cylindrical shape and then lifted together with the freezing pipe, the sample can be cored on the ground, so many specimens can be obtained for the amount of frozen soil.

  In Patent Document 6, a cryogenic fluid injection pipe and a circulating water pressure feed pipe for drilling and a digging discharge pipe are drilled in the center of the freezing pipe by a water jet from the bottom lid of the freezing pipe. Then, press the freezing pipe into the ground while discharging the debris at the top. A cryogenic fluid is injected from the top of the injection pipe, discharged from the lower end, and raised in the freezing pipe while exchanging heat to form a frozen soil column. Since the frozen soil is cut into a cylindrical shape and then the frozen soil is lifted together with the frozen tubes, there is little disturbance of the surrounding ground due to the insertion of the frozen tubes, and the ratio of the amount of frozen soil that can be used for the test to the amount of created frozen soil increases. Become.

  However, in the sampling method or sampling apparatus described in these documents, the freezing pipe is thin and self-excavated, the area of ground disturbance due to penetration can be reduced, and the diameter of frozen soil can be reduced. However, since the cryogenic fluid is discharged from the tip of the injection pipe, it rises while exchanging heat in the freezing pipe, and frozen soil is created, so the lower part of the created frozen soil pillar becomes thicker, the outer surface of the frozen soil and the ground It was difficult to pull out the frozen soil pillar due to the increased resistance to lifting.

  Also, since it is difficult to pull out the frozen soil pillar as it is, the periphery of the frozen soil pillar is cut into a cylindrical shape (cored) and then lifted up. There was a drawback that the coring work cost by a drilling machine was required.

Japanese Patent Application Laid-Open No. 60-1000073 Japanese Patent Laid-Open No. 61-251742 JP-A-61-251743 Japanese Patent Laid-Open No. 62-140043 Japanese Patent Laid-Open No. 03-286093 JP 07-127368 A

  In view of the above-described conventional drawbacks, the present invention provides a sampling method and a sampling apparatus for a ground sample that can quickly lift the frozen soil without cutting (coring) the outer periphery of the frozen ground sample (frozen soil column). It is aimed.

  In order to achieve the above object, the ground sample sampling method of the present invention includes a freezing tube insertion step of inserting a freezing tube into the soil from which the ground sample is collected, and cooling the freezing tube inserted in the freezing tube insertion step. A ground sample freezing step in which the ground sample around the freezing tube is frozen in a substantially inverted frustum shape with the freezing tube as a central axis, and the freezing tube is extracted from the soil together with the frozen ground sample, The ground sample collecting step is performed without coring around the frozen ground sample.

  The ground sample sampling device of the present invention includes a pipe-shaped rod, a freezing pipe having an upper end connected to the lower end of the rod and having a refrigerant flow path, and a refrigerant flow path of the freezing pipe. The ground sample freezing means is configured to supply a refrigerant and freeze the ground sample around the freezing tube in a substantially inverted frustum shape with the freezing tube as a central axis.

  Further, the ground sample sampling device of the present invention is provided with a cylindrical or columnar freezing tube installed in the soil, and an upper end portion of the freezing tube, and the ground sample around the freezing tube is used as the freezing tube. The center axis is composed of a cold heat source frozen in a substantially inverted frustum shape.

As is clear from the above description, the present invention has the following effects.
(1) In each of the inventions described in claims 1, 7, and 14, the ground sample around the freezing tube is frozen into a substantially inverted frustum shape or a substantially cylindrical shape. The resistance force can be prevented from increasing, and the ground sample can be easily pulled out.
For this reason, the construction period can be shortened and the construction cost can be reduced. Large-scale equipment for frozen ground coring and advanced technology can be eliminated, and the ground sample can be easily sampled.
(2) Further, the ground sample can be pulled out without coring around the frozen ground sample.
That is, ground freezing increases the work period and cost in terms of a geometrical series as the frozen soil thickness from the freezing pipe increases. In order to collect the frozen soil created in this way, it could not be pulled out by the conventional method, so the expensive outer peripheral frozen soil was cored and discarded, and only the frozen soil pillar portion was collected. However, by creating an inverted frustum-shaped frozen soil mass, it becomes possible to collect all the frozen soil without coring.
Therefore, since all the created frozen soil blocks can be collected, the ratio of the amount of frozen soil that can be used for the purpose of freezing sampling to the amount of created frozen soil can be dramatically improved.
(3) The inventions described in claims 2 to 6 and claims 9 to 13 can also achieve the same effects as the above (1) to (2).
(4) In the inventions described in claims 8 and 15, the same effects as in the above (1) and (2) can be obtained, and the frozen tube can be obtained without drilling the investigation hole in advance. Can be placed in the soil.

1 to 7 are explanatory views showing a first embodiment of the present invention.
8 to 11 are explanatory views showing a second embodiment of the present invention.
12 to 15 are explanatory views showing a third embodiment of the present invention.
16 to 19 are explanatory views showing a fourth embodiment of the present invention.
20 to 22 are explanatory views showing a fifth embodiment of the present invention.
The process figure of the sampling method of the ground sample of 1st Embodiment. The front view of the sampling apparatus of the ground sample of 1st Embodiment. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. Explanatory drawing of a freezing tube. Explanatory drawing of a freezing tube insertion process. Explanatory drawing of a ground sample freezing process (ground sample freezing means). Explanatory drawing of a ground sample collection process. Process drawing of the sampling method of the ground sample of 2nd Embodiment. The front view of the ground sample sampling apparatus of 2nd Embodiment. Illustration of freezing tube Explanatory drawing of a ground sample freezing means. Process drawing of the sampling method of the ground sample of 3rd Embodiment. The front view of the sampling apparatus of the ground sample of 3rd Embodiment. Illustration of freezing tube Explanatory drawing of a ground sample freezing means. Process drawing of the sampling method of the ground sample of 4th Embodiment. The front view of the ground sample sampling apparatus of 4th Embodiment. Illustration of freezing tube Explanatory drawing of a ground sample freezing means. Process drawing of the sampling method of the ground sample of 5th Embodiment. The front view of the sampling apparatus of the ground sample of 5th Embodiment. Explanatory drawing of a ground sample freezing means.

  Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings.

  In the first embodiment for carrying out the present invention shown in FIGS. 1 to 7, reference numeral 1 denotes a ground sample sampling method for obtaining characteristic values for obtaining ground liquefaction strength, dynamic deformation coefficient, and the like.

  As shown in FIG. 1, the ground sample sampling method 1 includes a freezing tube insertion step 4 in which a freezing tube 3 is inserted into the soil from which the ground sample 2 is collected, and the freezing tube 3 inserted in the freezing tube insertion step 4. The ground sample freezing step 5 in which the ground sample 2 around the freezing tube 3 is frozen in a substantially inverted frustum shape having a smaller diameter from the upper end to the lower end, and the ground sample 2 in which the freezing tube 3 is frozen. It is composed of a ground sample collection step 6 in which the ground sample 2 is extracted together from the soil.

  The ground sample sampling device 7 used in the ground sample sampling method 1 includes a pipe-shaped rod 8 and a lower end portion of the rod 8 as shown in FIGS. A freezing pipe 3 having an upper end connected thereto and having a refrigerant flow path 9 and a refrigerant 10 is supplied to the refrigerant flow path 9 of the freezing pipe 3 so that the ground sample 2 around the freezing pipe 3 has a substantially inverted frustum shape. It is comprised with the ground sample freezing means 11 to freeze.

  In the freezing tube insertion step 4, as shown in FIG. 5, the freezing tube 3 is inserted into the soil of the ground where the ground sample 2 is to be collected. In this step, there is a method of excavating a pilot hole in advance and inserting the freezing tube 3 into the soil. However, in this embodiment, the freezing tube 3 is provided with the excavating means 12 and the freezing tube 3 is formed while making a hole. Is a step of inserting (penetrating). For example, the freezing tube 3 attached to the tip of the rod 8 is installed in a predetermined soil while rotating and cutting gently by a rotary press-fitting machine (not shown).

  The excavating means 12 in the present embodiment includes a cutting blade 14 provided at the lower end of the freezing pipe 3 and a spiral blade 13 that excavates the ground by rotation and discharges the excavated earth and sand upward.

In the present embodiment, the freezing tube 3 has a cylindrical shape with the same diameter in the vertical direction and the bottom closed, and a spiral blade 14 is provided around the freezing tube 3. The spiral blade 13 is continuous in the present embodiment, but may be an intermittent spiral blade 13 in order to reduce rotational resistance.
After placing the freezing tube 3 in the soil, the freezing tube 3 is cooled, and a ground sample freezing step 5 is performed in which the ground sample 2 around the freezing tube 3 is frozen in a substantially inverted frustum shape. In this embodiment, the ground sample freezing means 11 for freezing the ground sample 2 in a substantially inverted frustum shape is controlled by controlling the surface temperature of the freezing tube 3 from the lower part to the upper part in order. Is frozen in a substantially inverted frustum shape.

  Specifically, refrigerant thermometers T1 and T2 are mounted on the side surfaces of the upper and lower ends of the refrigerant flow path 9 in the freezing pipe 3, and the control of the refrigerant supply uses the upper and lower temperature difference as an index. At the upper end of the freezing pipe 3, a low heat conduction disk 15 made of plywood with a target diameter of frozen ground is installed, and on the outer periphery, a specific resistance meter R is used instead of a thermometer to eliminate detection of ground freezing detection due to overcooling. Installing.

  A plurality of refrigerant injection holes 16 are formed in the peripheral wall of the refrigerant flow path 9 disposed inside the freezing pipe 3, and the refrigerant 10 is discharged from the refrigerant discharge holes 16 in the lateral direction. In the present embodiment, four coolant discharge holes 16 are formed at predetermined intervals in the circumferential direction, and a plurality of refrigerant discharge holes 16 are provided from the upper part to the lower part. The lower part is 22.5 cm pitch, the middle part is 9 cm pitch, and the upper part is 7.5 cm pitch. The refrigerant injection hole 16 is provided.

  The refrigerant 10 (liquid nitrogen) is injected from a heat-insulated injection connecting pipe (not shown) connected to the refrigerant flow path 9, and this control is performed by the control device C by setting the upper and lower temperatures of the refrigerant thermometer to a set value. Control the injection of the refrigerant 10 (so that the upper part is lower than the lower part of the freezing tube 3), and stop the injection of liquid nitrogen when it is detected from the resistivity meter R that the frozen soil has reached a predetermined diameter To do.

  In the present embodiment, the control device C controls the target value of the temperature difference between the upper thermometer T1 and the lower thermometer T2 outside the refrigerant flow path 9 in the freezing pipe 3 to be −60 to −70 ° C. Yes. For example, the temperature of the upper thermometer T1 is controlled to be −110 ° C. to −120 ° C., and the temperature of the lower thermometer T2 is controlled to be about −50 ° C. to −60 ° C. In order to control to such a temperature, the injection amount of the refrigerant 10 (liquid nitrogen) is controlled by opening and closing the electromagnetic valve, and the electromagnetic valve is opened and closed every 30 seconds. When the temperature is controlled to be as described above, freezing of the ground sample 2 starts about 5 minutes after the start of the injection of the refrigerant 10, and the ground sample freezing step 5 ends in about 30 minutes. The frozen ground sample 2 obtained in the ground sample freezing step 5 of the present embodiment has an inverted frustum shape having a length of about 1.0 m, a diameter of about φ4.5 cm at the lower end, and about φ11 cm at the upper end.

Further, the refrigerant 10 (liquid nitrogen) discharged from the refrigerant discharge hole 16 is vaporized and discharged to the upper side (rod 8) side from between the freezing pipe 3 and the refrigerant flow path 9.
In the ground sample freezing step 5, the ground sample freezing means 11 is used to freeze the ground sample 2 around the freezing tube 3 in a substantially inverted frustum shape.

  When the ground sample 2 around the freezing tube 3 freezes in a substantially inverted frustum shape, this ground sample 2 is pulled out of the soil together with the freezing tube 3 and a ground sample collecting step 6 for collecting the ground sample 2 is performed. When this ground sample collection step 6 is performed, the ground sample 2 is pulled out without coring the frozen ground sample 2.

Specifically, a lifting force is applied to the rod 8 using a jack (not shown). When the frozen ground sample 2 moves, the rod 8 is slowly rolled up by a winch (not shown), and the frozen ground sample 2 is wrapped. , Low temperature curing.
It should be noted that the position in the depth direction of the refrigerant discharge hole 16 of the refrigerant flow path 9, the number and diameter of the circumferential direction, the temperature difference index value above and below the freezing pipe, etc. It can change suitably from these.

[Different forms for carrying out the invention]
Next, different modes for carrying out the present invention shown in FIGS. 8 to 22 will be described. In the description of the different embodiments for carrying out the present invention, the same components as those in the first embodiment for carrying out the present invention are denoted by the same reference numerals, and redundant description is omitted.

  The second embodiment for carrying out the present invention shown in FIGS. 8 to 11 is mainly different from the first embodiment for carrying out the present invention in that a pipe-shaped freezing tube main body 17 and the freezing tube Refrigerant channel 9A provided so that the refrigerant flows spirally around the outer periphery of tube body 17, cladding tube 18 provided outside the refrigerant channel 9A, and excavation provided at the lower end of freezing tube 3A Using a freezing tube 3A made of a shoe as the means 12A, the refrigerant 10 is caused to flow from the upper part of the spiral refrigerant flow path 9A, and the surface temperature of the freezing pipe 3A is controlled so as to gradually decrease from the lower part to the upper part. The ground sample sampling method 1A for performing the ground sample freezing step 5A using the ground sample freezing means 11A and the ground sample sampling device 7A are used, and the first embodiment for carrying out the present invention is also provided with such a configuration. Same as Do effect can be obtained.

  Specifically, one or more refrigerant tubules (refrigerant) are provided outside the freezing pipe in which a water supply pipe 20 having a drilling port 19 for drilling is provided at the lower end on the inner wall of the freezing pipe and a refrigerant exhaust pipe after heat exchange. The flow path 9A) is spirally wound, the refrigerant 10 is injected from the upper end through the injection pipe 21, and after the heat exchange, the vaporized refrigerant 10 is exhausted from the lower end through the exhaust pipe 22, The inverted frustum-shaped frozen soil mass is created while injecting by controlling the difference in discharge temperature.

  Since the surface of the refrigerant flow path 9A made of the spiral pipe is not smooth and the penetration resistance of the freezing tube is large, the surface of the freezing tube is smoothed by covering with a cladding tube 18 formed of a thin copper tube having a good heat conductivity. As a result of increasing the diameter of the shoe (excavation means 12A) so as to be substantially flush with the cladding tube 18, the penetration resistance was reduced, but the heat transfer efficiency was reduced.

  Therefore, in the present embodiment, the cryopipe main body 17 made of, for example, SUS304 and the copper cladding tube 18 having a high thermal conductivity are used, which have substantially the same coefficient of thermal expansion and low thermal conductivity. A shoe 12A is attached to the outer periphery, and an outer periphery is formed with an angle thread equivalent to a helical tube for the refrigerant flow path 9A, and a copper cladding tube 18 is covered by applying the principle of shrink fitting so as to be crimped to the tip of the thread. ing.

  The third embodiment for carrying out the present invention shown in FIG. 12 to FIG. 15 is different from the second embodiment for carrying out the present invention mainly in the first embodiment for carrying out the present invention. The main difference from the configuration is that a multi-tube (double tube in this embodiment) freezing tube 3B is used, and a refrigerant flow path 9B is provided between an inner pipe and an outer pipe of the freezing pipe 3B. Sampling of the ground sample which performs the ground sample freezing process 5B using the ground sample freezing means 11B which controls the surface temperature of the freezing pipe 3B to be gradually lowered from the lower part to the upper part by flowing the refrigerant 10 from the upper part of 9B. Even in such a configuration, the same effect as that of the first embodiment for carrying out the present invention can be obtained by using the method 1B and the ground sample sampling device 7B. That is, the upper part of the freezing pipe 3B can be made lower than the lower part of the freezing pipe 3B by allowing the freezing pipe 3B to be a multiple pipe and flowing the refrigerant 10 from the upper part of the refrigerant flow path 9B while controlling the difference between the injection temperature and the discharge temperature. It can be frozen in a substantially inverted frustum shape or a substantially cylindrical shape.

  In the present embodiment, a double pipe freezing pipe 3B is used, and a gap between the outer pipe 3a and the inner pipe 3b of the freezing pipe 3B is used as a refrigerant flow path 9B, and the refrigerant 10 is injected into this portion to exchange heat with the surrounding ground. Then, it flows down and rises from the lower end to the inside of the inner pipe and is exhausted.

  As in this embodiment, instead of a double pipe, the freezing pipe 3B is a triple pipe or the like, and the gap between the outermost pipe and the middle pipe is a refrigerant flow path 9B. Then, the gap between the middle pipe and the inner pipe at the center may be raised from the lower end portion and exhausted.

  The fourth embodiment for carrying out the present invention shown in FIGS. 16 to 19 is mainly different from the first embodiment for carrying out the present invention in that the freezing is gradually reduced in diameter from the upper part to the lower part. The ground sample sampling method 1C for performing the ground sample freezing step 5C using the ground sample freezing means 11C that freezes the ground sample in a substantially inverted frustum shape by cooling the freezing tube 3C using the tube 3C and the ground sample Even in such a configuration, the same effect as that of the first embodiment for carrying out the present invention can be obtained by using the sampling device 7C.

  As the ground sample freezing means 11C of this embodiment, the inside of the freezing pipe 3C is used as a refrigerant flow path 9C, and the refrigerant flow path 9C is filled with the refrigerant 10 (liquid nitrogen), and the temperature inside the freezing pipe 3C is always set. Hold constant. By cooling in this way, the thickness of the ground sample can be made almost constant, and the ground sample having the same gradient as the outer peripheral surface of the freezing tube 3C can be sampled.

  The fifth embodiment for carrying out the present invention shown in FIGS. 20 to 22 is mainly different from the first embodiment for carrying out the present invention in that a cylindrical or columnar shape installed in the soil is used. A ground sample that freezes the ground sample around the freezing tube 3D into a substantially inverted frustum shape or a substantially cylindrical shape by cooling using the freezing tube 3D and the cold heat source 23 provided at the upper end of the freezing tube 3D. The ground sample sampling method 1D for performing the ground sample freezing step 5D using the freezing means 11D and the ground sample sampling device 7D are used, so that the first embodiment for carrying out the present invention even with such a configuration is used. The same effect can be obtained.

  By providing a cooling heat source 23 at the upper end of the freezing tube 3D to cool the freezing tube 3D, the upper part becomes colder than the lower part of the freezing tube 3D, and the ground sample is frozen in a substantially inverted frustum shape or a substantially cylindrical shape. Can be made.

  The present invention is used in the industry of sampling for obtaining ground physical property information.

1, 1A, 1B, 1C, 1D: Sampling method of ground sample,
2: Ground sample, 3, 3A, 3B, 3C, 3D: Cryotube,
4: Freezing tube insertion process,
5, 5A, 5B, 5C, 5D: Ground sample freezing step,
6: Ground sampling process,
7, 7A, 7B, 7C, 7D: ground sample sampling device,
8: Rod, 9, 9A, 9B, 9C: Refrigerant flow path,
10: refrigerant,
11, 11A, 11B, 11C, 11D: ground sample freezing means,
12, 12A: Excavation means, 13: Spiral blade,
14: Cutting blade, 15: Low heat conduction disk,
16: Refrigerant injection hole, 17: Freezing pipe body,
18: cladding tube, 19: jet nozzle,
20: Water supply pipe, 21: Injection pipe,
22: Exhaust pipe, 23: Cold source.

Claims (15)

A freezing tube insertion step in which a freezing tube is inserted into the soil from which the ground sample is collected, and the freezing tube inserted in the freezing tube insertion step is cooled, and the ground sample around the freezing tube is used as a central axis. It consists of a ground sample freezing step that freezes in a substantially inverted frustum shape, and a ground sample sampling step in which the freezing tube is extracted from the soil together with the frozen ground sample and the ground sample is collected. The sampling method of the ground sample performed without coring around the frozen ground sample. 2. The ground sample freezing step, wherein the surface temperature of the freezing tube is controlled so as to gradually decrease from the lower part toward the upper part, and the ground sample is frozen in a substantially inverted frustum shape. Sampling method for ground samples. In the ground sample freezing step, the refrigerant is flown from the upper part to the refrigerant flow path which is arranged inside the freezing pipe and has a plurality of refrigerant injection holes from the upper part to the lower part on the peripheral wall, and the refrigerant is injected from the refrigerant injection holes, The ground sample sampling method according to claim 2, wherein the surface temperature of the freezing tube is cooled so as to gradually decrease from a lower part toward an upper part. In the ground sample freezing step, a pipe-shaped freezing tube main body, a refrigerant channel provided on the peripheral side surface of the freezing tube main body so that the refrigerant flows in a spiral shape, and an outer side surface of the refrigerant channel are provided. Using a freezing tube made of a clad tube, flowing a refrigerant from the upper part of the spiral refrigerant flow path, and cooling the surface temperature of the freezing pipe so as to gradually decrease from the lower part to the upper part. The ground sample sampling method according to claim 2. In the ground sample freezing step, a multi-tube freezing tube is used, and a refrigerant flow path is formed between the inner tube and the outer tube of the freezing tube, and the refrigerant is allowed to flow from the upper portion of the refrigerant flow path. The ground sample sampling method according to claim 2, wherein the ground sample is cooled from the lower part to the upper part in order so that the temperature becomes lower. 2. The ground sample freezing step uses a freezing tube having a diameter that gradually decreases from an upper part to a lower part, and the freezing pipe is cooled to freeze the ground sample in a substantially inverted frustum shape. The sampling method of the ground sample as described in 4. A pipe-shaped rod, a freezing pipe having an upper end connected to the lower end of the rod and having a refrigerant flow path, and supplying a refrigerant to the refrigerant flow path of the freezing pipe, and a ground around the freezing pipe A ground sample sampling device comprising a ground sample freezing means for freezing the sample in a substantially inverted frustum shape with the freezing tube as a central axis. The ground sample sampling device according to claim 7, wherein the freezing pipe further includes excavation means for excavating the ground. The said ground sample freezing means controls the surface temperature of the said freezing tube so that it may become low temperature sequentially from the lower part toward the upper part, and freezes a ground sample to a substantially inverted frustum shape. Item 9. The ground sample sampling device according to any one of Items 8 to 9. The ground sample freezing means is disposed inside the freezing pipe, and a refrigerant is flowed from the upper part to a refrigerant flow path having a plurality of refrigerant injection holes from the upper part to the lower part of the peripheral wall thereof, and the refrigerant is injected from the refrigerant injection holes, The ground sample sampling device according to claim 9, wherein the surface temperature of the freezing tube is cooled so as to gradually become lower from the lower part toward the upper part. The ground sample freezing means includes a pipe-shaped freezing tube main body, a refrigerant flow path provided in such a manner that a refrigerant flows spirally around the outer periphery of the freezing pipe main body, and a cladding tube provided outside the refrigerant flow path 10. A cryopipe comprising: a refrigerant flow from an upper part of the spiral refrigerant flow path, and the surface temperature of the freeze pipe is cooled gradually from the lower part toward the upper part. The ground sample sampling device described in 1. The ground sample freezing means uses a multi-tube freezing tube, a refrigerant channel is formed between the inner tube and the outer tube of the freezing tube, and the refrigerant flows from the upper part of the refrigerant channel, and the surface temperature of the freezing tube The ground sample sampling device according to claim 9, wherein the ground sample is cooled from the lower part to the upper part in order so that the temperature becomes lower. The ground sample freezing means uses a freezing tube that gradually decreases in diameter from the upper part toward the lower part, and freezes the ground sample in a substantially inverted frustum shape by cooling the freezing tube. The ground sample sampling device according to claim 8. Cylindrical or columnar freezing tube installed in the soil, and cooling heat provided at the upper end of the freezing tube and freezing the ground sample around the freezing tube in a substantially inverted frustum shape around the freezing tube A ground sample sampling device composed of a source. The ground sample sampling apparatus according to claim 14, wherein the freezing pipe further includes excavation means for excavating the ground.

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