JP3326463B2 - In-situ test equipment to determine horizontal stress of ground due to in-situ ground freezing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-situ test apparatus used to freeze in-situ sandy ground or gravel ground in situ and directly determine in-situ horizontal stress of the ground. .

[0002]

2. Description of the Related Art In the field of geotechnical engineering, estimation and confirmation of a stress state at an original position of the ground is one of important matters. For cohesive ground, the in-situ stress state has been measured to some extent. However, sandy ground,
For so-called non-viscous ground such as gravel ground, the in-situ stress state cannot be measured accurately yet.

Conventionally, when the in-situ ground is frozen in a one-dimensional state, the state of stress and strain in the in-situ ground is preserved as it is. When a test hole is excavated in this frozen ground and the frozen ground is thawed while restraining the horizontal strain of the hole wall, it is possible to obtain the horizontal stress of the actual ground. In-situ test methods and devices for determining the horizontal stress in the ground have already been studied, and are disclosed, for example, in JP-A-1-250591 and JP-A-3-284.
It is described in, for example, Japanese Patent Publication No. 90 and belongs to the public domain.

The in-situ test apparatus described in Japanese Patent Application Laid-Open No. 3-28490 will be outlined below with reference to FIG. A cylindrical rubber sleeve 40 is placed concentrically around the outer periphery of a cylindrical device housing 41 having a slightly smaller outer diameter, and an annular sleeve completely sealed between the rubber sleeve 40 and the outer peripheral surface of the device housing 41. A pressure space 42 is formed. Upper and lower ends of the rubber sleeve 40 are fixed to each other by a tightening ring 44, a taper ring 45 and a press ring 43. The cell liquid supply pipe 4 is provided below the pressurized space 42 from inside the hollow portion of the device housing 41.
The pressurized space 42 is filled with a cell liquid such as degassed water or antifreeze. A heater 52 for humidifying the cell liquid is also provided in the pressurized space 42. A two-way solenoid valve 54 is connected in the middle of the cell liquid supply pipe 47. A two-way solenoid valve 54 is branched by the two-way solenoid valve 54 to reach a water head pipe 55 arranged vertically upward. A differential pressure gauge) 56 is provided. A pneumatic tube 57 connected from an air pressure control mechanism 61 on the ground is commonly connected to the upper ends of the differential pressure transducer 56 and the head tube 55. The cell liquid supply port of the two-way solenoid valve 54 is connected to a cell liquid supply pipe 5 piped from a cell liquid supply mechanism 48 on the ground.
3 are connected. On the lower surface of the apparatus housing 41, a water pressure detector 58 for measuring the water pressure of the hole wall stabilizing liquid filled in the test hole 9 is installed facing downward.

This in-situ test apparatus is used by being inserted from the ground into a test hole 9 excavated in the frozen in-situ ground, which is attached to the tip of a rod 59. The test solution is prepared by supplying the cell liquid to the test pressurizing space 42 to expand the rubber sleeve 40 and abut the hole wall surface,
Wait for the in-situ frozen ground to thaw. Deformation of hole wall due to stress release along with melting of frozen ground (horizontal strain)
Is restrained by adjusting the cell liquid pressure in the test pressurized space 42 (keeping the so-called K ₀ state for controlling the deformation to zero), the cell at the time when the frozen ground in the original position is completely thawed The liquid pressure is determined as the horizontal stress of the in-situ ground.

The differential pressure transducer 56 detects the deformation (horizontal distortion) of the hole wall, and the air pressure adjusted by the air pressure control mechanism 61 on the ground is applied to the cell liquid through the head tube 55 to reduce the deformation of the hole wall to zero. The feedback control is performed so as to return to. During that time, the heater 52 heats the cell liquid in the test pressurized space 42 in contact with the frozen ground, and keeps the temperature substantially constant to prevent the occurrence of measurement errors. The cell liquid pressure in the test pressurized space 42 required to maintain the K ₀ state was measured by the air pressure gauge 6.
The horizontal stress (effective stress) of the in-situ ground (actual ground) is calculated by comparing the measured value with the in-hole water pressure obtained at the in-situ position obtained by the water pressure detector 58. Desired.

In FIG. 4, reference numeral 50 denotes a deaeration nozzle from the deaeration section 49, to which an air vent valve 51 is attached.
The air pressure control mechanism 61 includes an air pressure controller 66 driven by a servo motor 65.
Is connected to an air pressure source 60. The differential pressure transducer 5
The measured value of the horizontal strain measured at 6 is the strain amplifier 6
3 and the servo motor 65 is automatically controlled by the output of the servo controller 64 based on the input.

[0008]

[Problems to be Solved by the Invention] In order to smoothly insert and install the in-situ test apparatus into the test hole 9,
The diameter of the test hole 9 is formed slightly larger than the outer diameter of the test device. For this reason, the upper and lower hole walls adjacent to the hole wall portion whose deformation is restrained by the rubber sleeve 40 forming the outer peripheral surface of the test pressurizing space 42 of the conventional in-situ test apparatus shown in FIG. It deforms freely along with and collapses. As a result, it is presumed that the influence of the deformation and collapse of the adjacent hole wall has a greater or lesser effect on the hole wall of the test portion constrained by the rubber sleeve 40, which causes a test error. Need to be resolved. A general method of using the in-situ test apparatus is to inject an appropriate amount of a cell solution in advance on the ground and insert the cell solution into the test hole 9 of the frozen ground, but it is usually filled with an antifreeze solution (stable solution) at about -20 ° C. The cell liquid is cooled strongly during the preparation for the test by lowering it into the test hole 9 to the target test position. In particular, the water in the thin and long water head tube 55 freezes (see FIG. 4), and a change in the volume of the cell liquid in the test pressurized space 42 is not accurately converted into a change in the water level. Inconvenience can occur.
Similarly, in order to prepare the test of the in-situ test device inserted into the test hole 9, even if the cell liquid is supplied from the cell liquid supply mechanism 48 on the ground, the cell liquid supply pipe 53 ( 4 water in the reference) can occur a disadvantage that becomes impossible supply Mai and frozen.

Accordingly, an object of the present invention is to solve the above-mentioned problems, and in particular, to provide an upper and lower free hole wall portion adjacent to a hole wall portion whose deformation is restrained by a rubber sleeve forming an outer peripheral surface of a test pressurizing space. It is an object of the present invention to provide an in-situ test apparatus in which a test error caused by deformation and collapse is prevented beforehand and test accuracy is improved.

[0010]

As a means for solving the above-mentioned problems of the prior art, an in-situ test apparatus for determining the horizontal stress of the ground due to the in-situ ground freezing according to the first aspect of the present invention is as follows . The rubber sleeve 40 is inserted into a test position in the test hole 9 having a desired depth excavated in the frozen ground, and the peripheral side surface of the pressurized space 42 formed by the rubber sleeve 40 is expanded to abut against the wall surface of the hole. In this way, the test preparation is prepared, and the horizontal strain in which the ground tries to deform in the radial direction of the test hole 9 as the frozen ground in the original position melts is restrained by the fluid pressure acting on the rubber sleeve 40.
Performs control to maintain the K ₀ state and, in situ testing apparatus for determining the fluid pressure acting on the rubber sleeve 40 when the freezing ground in situ was completely melted the horizontal stress in situ ground, peripheral The pressurized space formed by a rubber sleeve on the side is composed of an original test pressurized space 42 and independent auxiliary pressurized spaces 42a, 4
2b are formed in such a manner that at least three of them are arranged in the axial direction of the test apparatus, and the test pressurizing space 42 and the two auxiliary pressurizing spaces 42a, 42b are respectively independent supply systems 47, The cell liquid is filled with 86, 87 and the cell liquid pressure acting on each rubber sleeve 40, 40a, 40b is controlled by an independent pressure control system 55, 56, 57 and 82, 84, 85. (FIG. 1).

[0011] The invention according to claim 2 is described in claim 1.
In-situ for calculating horizontal stress of ground due to ground freezing
In the test apparatus, the cell liquid supply pipes 47 and 8 connected to the test pressurizing space 42 and the auxiliary pressurizing spaces 42a and 42b.
The two-way solenoid valves 54 and 81 are respectively provided in the middle of 6 and 87, and the water head pipes 55 and 85 branched by the two-way solenoid valves 54 and 81 and arranged vertically upward are insulated containers attached to the apparatus housing 41. 10 storage to be installed in the
The sealing water 11 is filled to the extent that the head tube 55 is submerged in the heat insulating container 10, and a heater 12 for heating the sealing water 11 and a temperature sensor 13 for measuring the water temperature of the sealing water 11 are provided. (Chart
2). The invention described in claim 3 is described in claim 1 or 2.
In-situ for calculating horizontal stress of ground due to ground freezing
In the test apparatus, the peripheral side surface is <br/> formed between pressurized rubber sleeve device c c Managing 41 heat insulation of the cell fluid container 2
0 is attached, the cell liquid 21 is accommodated in the cell liquid container 20, the cell liquid supply pipe 23 connected to the cell solution outlet 19 of the cell fluid container 20 and 23 'through the two-way solenoid valve 54,81 being connected rubber sleeve 40 and 40a, inside the pressurized space 42 and 42a of 40b, and 42b and water head tube 55,85, and airbag into the cell solution vessel 20
Grayed 24 is installed, the airbags 24 of the air entrance 2
5 that it is connected to the ground of the pneumatic control mechanism and it <br/> respectively, wherein (Fig. 3).

[0012]

(A) The hole walls adjacent to the upper and lower sides of the hole wall whose deformation is restricted by the rubber sleeve 40 forming the outer peripheral surface of the test pressurizing space 42 are the outer periphery of the upper and lower auxiliary pressurizing spaces 42a and 42b. The deformation is similarly restricted by the rubber sleeves 40a and 40b forming the surfaces. Therefore, the influence of the deformation and collapse of the vertically adjacent unconstrained free-deformable hole wall portion hardly affects the hole wall portion restrained by the rubber sleeve 40 of the test pressurizing space 42, and high test precision is achieved. Can be secured. (B) The long and narrow head tube 55 is firstly protected from the cold transmitted from the outer periphery by the heat insulating container 10. Secondly, the sealing water 11 accommodated in the heat insulating container 10 is also protected from cooling. In addition, the temperature of the sealing water 11 is
And the temperature of the sealed water 11 is maintained at a substantially constant temperature through the temperature control device. Therefore, there is no possibility that the water in the water head tube 55 freezes, and the test error due to the temperature difference (change in volume of water) is minimized. Can be (C) The amount of cell liquid 21 required for the function of the in-situ test apparatus is stored in advance in the heat-insulating cell liquid container 20 on the ground, and lowered into the test hole 9 together with the test apparatus. The cell liquid 21 accommodated in the heat-insulating cell liquid container 20 is protected from strong cooling from the surroundings, so that there is no fear of freezing. When inflating the air bag 24 by operating the ground of the pneumatic control mechanism, the expansion volume equivalent cell liquid 21 is fed from the cell liquid container 20, between the test pressurized via the two-way solenoid valve 54 42 Alternatively, the auxiliary pressurizing spaces 42a, 42
b. Accordingly, the cell liquid supply pipe (reference numerals 48 and 53 in FIG. 4) for connecting the in-situ test apparatus and the cell liquid supply mechanism on the ground (see reference numeral 48 in FIG.
It is unnecessary to replenish the cell solution by preparing the cell solution. Therefore, there is no risk of trouble caused by freezing of water in the cell liquid supply pipe.

[0013]

Next, an embodiment of the present invention shown in FIGS. 1 to 3 will be described. Most of the configuration principle, usage, and operation (function) of the in-situ test apparatus shown in FIGS. 1 to 3 are almost the same as those of the above-described apparatus of FIG. 4, and thus redundant description will be omitted. First,
The in-situ test apparatus shown in FIG. 1 has a cylindrical shape (φ190, approximately 350 mm in length) having substantially the same diameter as the diameter of a test hole (see reference numeral 9 in FIG. 4) formed in the in-situ frozen ground. Eggplant top and bottom 3
The rubber sleeves 40 and 40a and 40b are concentrically arranged on the outer periphery of a cylindrical device housing (hereinafter simply referred to as a housing) 41 having a slightly smaller outer diameter (φ160), and the outer peripheral surfaces of the rubber sleeve and the housing are provided. Annular pressurized spaces 42 and 42a, 42b completely sealed between
Are formed independently and vertically adjacent to each other. Reference numeral 42 denotes an original test pressurizing space, and reference numerals 42a and 42b denote auxiliary pressurizing spaces provided above and below the test pressurizing space 42. In the embodiment of FIG. 1, the upper and lower three rubber sleeves 40, 40a, and 40b are formed as a series, and the boundary between the pressurizing spaces 42, 42a, and 42b is fastened and fixed by the fixing ring 80. However, it is also possible to form and implement the rubber sleeve as an independent member for each pressurized space. Both ends of the rubber sleeve are, more specifically, as shown in detail in FIGS.
Taper ring 45 with tightening ring 44 screwed into
By pressing it, it is firmly fixed by the wedge effect and water
Denseness is maintained. The three pressurized spaces 42 and 42
a and 42b are respectively provided with cell liquid supply pipes 47, 86 and 87 from the hollow portion of the cylindrical housing 41 through the nozzle 46.
And three pressurized spaces 42 and 42a, 42
Cell fluid, such as degassed water or antifreeze, is filled in b with a separate supply system. In addition, each pressurized space 42 and 4
2a and 42b, the temperature of the cell solution was about 12 ° C. during the test.
Kept in the range of to 13 ° C., flex heating data 5 2 to prevent a test error caused by the volume change of the cell solution is placed.
The temperature of the cell liquid in each pressurized space 42 and 42a, 42b is measured by a thermocouple 39, and a temperature control mechanism on the ground (not shown)
Is managed by Two-way solenoid valves 54 and 54 'and 81 and 83 are provided in the middle of the cell liquid supply pipes 47, 86 and 87, and a pipe branched by the upper two-way solenoid valves 54' and 83 is hollow in the housing 41. It is connected to the head tubes 55 and 85 which are arranged vertically upward in the upper part of the part.

An amount of cell liquid necessary for use of this in-situ test apparatus is provided in a protective case 41b attached to a lower part of a housing 41 by attaching a cell liquid container 20 made of a heat insulating material.
It is contained in the cell liquid container 20. Cell liquid container 20
An airbag 24 is installed inside the container 20 so as to be inflatable to a volume equal to the internal volume of the container 20, and air is sent from an air pressure control mechanism on the ground through an air pipe 90 connected to the air inlet / outlet 25 of the airbag 24. 24 is expanded to an appropriate size (volume), and a cell liquid corresponding to the volume expansion is sent out. The cell liquid container 20 is provided with two cell liquid delivery pipes 23 and 23 '. One of the cell liquid delivery pipes 23 is provided with a two-way solenoid valve 54, a differential pressure transducer 56, and a cell liquid supply pipe 47 reaching the test pressurizing space 42. Two two-way solenoid valves 54 'are provided and connected to a head tube 55 above them. A pneumatic tube 57 piped from a pneumatic control mechanism not shown on the ground (see reference numerals 61 and 62 in FIG. 4) is branched in the middle and connected to the water head tube 55 and the differential pressure converter 56. .

The other cell liquid delivery pipe 23 'is also provided with a two-way solenoid valve 81, and the pipe ahead of the two-way solenoid valve 81 is connected to the cell liquid supply pipe 87 reaching the lower auxiliary pressurizing space 42b and the upper cell liquid supply pipe 87. A differential pressure converter 82 is provided in the middle of the liquid supply pipe 86 which branches off with the cell liquid supply pipe 86 reaching the auxiliary pressurizing space 42a and rises vertically. Further, the cell liquid supply pipe 86
A second two-way solenoid valve 83 is provided at the upper part of the head, and is connected to a head tube 85 above the second two-way solenoid valve 83. A pneumatic pipe 84, also plumbed from a pneumatic control mechanism on the ground (similar to the pneumatic control mechanism relating to the pneumatic pipe 57, but an independent mechanism), is branched into two pipes on the way, and 85 and a differential pressure converter 82.

Accordingly, the in-situ test apparatus is attached to the tip of the boring rod 59 and lowered into the test hole 9 (see FIG. 4). By inflating the bag 24, the test pressurizing space 42 and the auxiliary pressurizing spaces 42a, 42b
Supply or replenish the cell liquid. Thereafter, the head pipes 55 and 85 and the differential pressure transducer 5 are passed through the pneumatic control mechanism on the ground.
Air pressure is applied to 6 and 82 to displace the radial direction (horizontal direction) of the hole wall on the rubber sleeve 40 of the test pressurizing space 42 and the rubber sleeves 40a and 40b of the auxiliary pressurizing spaces 42a and 42b above and below. To zero (so-called K ₀
(The state is maintained.) A strong cell liquid pressure is applied. Thus, the cell liquid pressure in the test pressurized space 42 at the time when the in-situ frozen ground is completely thawed is, for example, the magnitude of the air pressure in the pneumatic tube 57 applied to the head tube 55 and the differential pressure converter 56. The air pressure shown in FIG. 4 is read by the meter 62, and a true horizontal stress is obtained.

[0017]

FIG. 1 shows another embodiment of the present invention.
5 slightly protrudes above the device housing 41. In addition, in the conventional example shown in FIG.
Is completely exposed above. Therefore, the water head tubes 55 and 85 are strongly cooled by cooling the hole wall stabilizing liquid at about −20 ° C. filled in the test holes, and there is a disadvantage that water (cell liquid) in the tubes freezes. In order to avoid such inconvenience, in the embodiment of FIG. 2, the water head tube 55 (and the water head tube 85 are also the same. However, specific illustration is omitted. The same applies hereinafter) made of acrylic resin having excellent heat insulating properties. It is installed vertically at the center of the transparent heat-insulating container 10 having a vertical cylindrical shape. Insulated container 10 is placed in the upper part of the hollow portion of the upper water-tightly spliced transparent acrylic resin cylindrical portion 41a of the housing 41. However,
The location is not limited to the embodiment. Sealing water 11 for heat insulation is filled in the heat insulating container 10 at a level to submerge the entire water head tube 55, and a heater 12 for heating the sealing water 11 is also provided. Further, thermocouples 13 as temperature sensors are provided above and below the heat insulating container 10. Measured value of the thermocouple 13 is inputted to the ground temperature control mechanism (not shown), the temperature of sealing water 11 by heating the heater 12 in the case of the water temperature is the downside, about the water temperature thus Mizuatamakan 55 Temperature control for keeping the temperature between 12 ° C and 13 ° C is performed.
Therefore, there is no concern about freezing of water in the head tube 55,
There is no concern about test errors due to changes in water volume. At the upper part of the heat insulating container 10, a water reservoir 72 having a considerably large capacity and communicating with the water head tube 55 is provided. This is because even when the water in the head tube 55 overflows during the test preparation, the overflow water is stored in the water sump 72 so as not to enter the pneumatic tube 57 above the position. is there.

The end plate 30 to the upper end of the acrylic resin cylindrical portion 41a is installed water-tightly, in the upper central portion of the end plate 30, a joint portion 31 for joining the boring rod 59 which is supported on the ground Is provided. Reference numeral 29 in FIG. 2 denotes a waterproof metal outlet provided for connection of each control signal line and the like. next,
FIG. 3 shows an embodiment of a different configuration of the cell liquid container portion incorporating the airbag 24. A protective case 41b made of stainless steel is added to the lower end of the housing 41, and a cell liquid container 20 made of a heat insulating synthetic resin and having a closed container structure is accommodated in a hollow portion of the protective case 41b. The cell liquid container 20 is formed in functionally required capacity capable of housing a cell solution 21 of the amount of the situ testing apparatus. The cell liquid container 20 has a cell liquid outlet hole 22 having an outlet 22a near the bottom thereof.
Is penetrated to the upper end. The cell liquid outlet hole 2
The outlet nozzle 19 attached to the upper end outlet of the second 2 is provided with a two-way electromagnetic force for the auxiliary pressurizing space 42b by a cell liquid supply pipe 23 '(and the cell liquid supply pipe 23 is also the same, but not shown). It is connected to the nozzle 18 of the valve 81.
An airbag 24 having an air inlet / outlet nozzle 25 on the top end wall of the cell liquid container 20 is housed in the cell liquid container 20. The cell liquid 21 pushed out from the cell liquid container 20 by inflating the airbag 24 is supplied to the cell liquid supply pipe 2.
The test pressurizing space 42 or the auxiliary pressurizing spaces 42a and 42b are passed through the two-way solenoid valves 54 and 81 from 3, 23 '.
Supplied to An air pressure tube 90 is connected to the air inlet / outlet nozzle 25 of the airbag 24, and is connected to an air pressure control mechanism (not shown) on the ground.

During the preparation of the test by lowering the in-situ test device into the test hole and during the test, the water temperature of the cell liquid in the test pressurizing space 42 and the auxiliary pressurizing spaces 42a and 42b is adjusted. Is controlled in the range of about 12 ° C. to 13 ° C., and the temperature control for keeping the temperature of the water in the water head tube 55 substantially constant is performed by measurement by the temperature sensors 39 and 13 and heating by the heaters 52 and 12. Test accuracy is ensured.

[0020]

According to the in-situ test apparatus according to the present invention, the horizontal stress of the ground due to the in-situ ground freezing is
The adverse effects of the deformation and collapse of the upper and lower hole walls adjacent to the hole wall portion confined by the rubber sleeve 40 of the test pressurizing space 42 are prevented by the rubber sleeves 40a and 40b of the upper and lower auxiliary pressurizing spaces 42a and 42b. Is required with high accuracy. In addition, there is no need to worry about troubles due to freezing of the cell liquid, and a highly accurate and highly reliable test can be performed in a state where there is almost no error caused by a change in water temperature (a change in water volume).

[Brief description of the drawings]

FIG. 1 is a simplified sectional view showing an embodiment of an in-situ test apparatus according to the present invention.

FIG. 2 is a sectional view showing the upper half of another embodiment of the in-situ test apparatus according to the present invention.

FIG. 3 is a sectional view showing a lower half of the in-situ test apparatus of FIG. 2;

FIG. 4 is a sectional view of a conventional in-situ test apparatus.

[Explanation of symbols]

 Reference Signs List 9 Test device 40 Rubber sleeve 40a, 40b Rubber sleeve 42 Test pressurization space 42a, 42b Auxiliary pressurization space 47 Cell liquid supply pipe 86, 87 Cell liquid supply pipe 55 Water head pipe 85 Water head pipe 10 Insulated container 11 Sealing Water 12 Heater 13 Thermocouple 20 Cell liquid container 21 Cell liquid 23 Supply pipe 24 Air bag

──────────────────────────────────────────────────続 き Continued on the front page (72) Yoshio Suzuki, Inventor 2-5-1-14 Minamisuna, Koto-ku, Tokyo Inside the Technical Research Institute, Takenaka Corporation (72) Inventor Akihiko Uchida 5-14, Minamisuna, Koto-ku, Tokyo No. Takenaka Corporation Technical Research Institute Co., Ltd. (72) Inventor Atsura Ohara 2--11-16 Higashigaoka, Meguro-ku, Tokyo Tokyo 72 Co., Ltd. No. 16 Inside Tokyo Soil Research Co., Ltd. (72) Inventor Naoto Takehara 2--11 Higashigaoka, Meguro-ku, Tokyo No. 16 Inside Tokyo Soil Research Co., Ltd. (72) Inventor Yasushi Kanzaki 8--21 Ginza, Chuo-ku, Tokyo No. 1 Takenaka Civil Engineering Co., Ltd. (72) Inventor Shuji Sakaguchi 8-21-1, Ginza, Chuo-ku, Tokyo Co., Ltd. Document JP Akira 55-81926 (JP, A) JP flat 1-250591 (JP, A) (58 ) investigated the field (Int.Cl. ^7, DB name) E02D 1/00 E21B 47/06

Claims (3)

(57) [Claims] 1. The rubber sleeve is inserted into a test position in a test hole of a desired depth excavated in a frozen ground, and a peripheral side surface of the rubber sleeve in a pressurized space formed by a rubber sleeve is expanded to abut against a wall surface of the hole. In this way, the test preparation is prepared, and the horizontal strain in which the ground tends to deform in the radial direction of the test hole as the frozen ground in the original position thaws is restrained by the fluid pressure acting on the rubber sleeve and K _0. In the in- situ testing device, which performs control to maintain the state and obtains the fluid pressure acting on the rubber sleeve as the horizontal stress of the in-situ ground when the in-situ frozen ground is completely thawed, The formed pressurized space is formed by arranging at least three of the original test pressurized space and independent auxiliary pressurized spaces provided vertically above and below the test pressurized space in the axial direction of the test apparatus. Formed And are each independently cell liquid in supply system has is satisfied, and the cell liquid pressure acting on the rubber sleeve by an independent pressure control system is controlled in the between the inter test pressurized and two auxiliary pressurized An in-situ test apparatus for determining horizontal stress in the ground due to in-situ ground freezing. 2. A two-way solenoid valve is provided in the cell liquid supply pipe connected to the test pressurizing space and the auxiliary pressurizing space, respectively, and is branched by the two-way solenoid valve to be arranged vertically upward. The water head tube is housed and installed in an insulated container attached to the device housing, and is filled with sealing water to such an extent that the head tube is submerged in the heat insulating container, and a heater for heating the sealed water, and wherein the temperature sensor for measuring the temperature of the sealing water is attached, according to claim 1
An in-situ test apparatus for determining the horizontal stress of the ground due to the in-situ ground freezing described in (1). 3. A peripheral side surface cell liquid container thermal insulation device c c Managing formed between pressurized rubber sleeve is attached, the cell solution into the cell liquid container is accommodated, the cells of the cell fluid container that the cell liquid supply tube connected to a liquid outlet which is connected to the inner pressure space and water head tube of the rubber sleeve via the two-way solenoid valves, and airbags <br/> is in the cell fluid container is installed, the air inlet and outlet of the airbags, each characterized in that it is connected to the ground of the pneumatic control mechanism, in situ testing for determining the horizontal stress of the ground according situ ground freezing according to claim 1 or 2 apparatus.