JP3361483B2 - Functional bore tester - 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-hole load testing apparatus for performing horizontal load test and shear test of a hole wall in a geological survey boring hole and obtaining ground information by an in-situ test.

[0002]

2. Description of the Related Art Among the in-situ in-hole tests, the "in-hole horizontal loading test method", in which a hole wall is pressed by an expansive cell to carry out a horizontal loading test, is the standard of the Japan Geotechnical Society (GJS1421-
1995). This test is a pre-boring method in which a cell is inserted into the hole and then a loading test is performed after boring. In addition to this, there is a self-boring type in which a cutting shoe is attached to the lower end of the cell to set the cell while excavating. Further, in addition to the above, in the hole wall test, a shearing device under pressure is applied to the hole wall to develop an internal friction angle of the ground, an adhesive force, and a test device for obtaining shear strength (for example, Patent No. 690755). No .: Ground shear test equipment).

[0003]

The pre-boring type horizontal loading test method in a hole is premised on that the hole wall does not collapse before the cell is set after boring. Therefore, it may not be possible to measure on collapsible ground. In addition, there are problems such as the disturbance of the ground due to drilling, the release of the ground pressure and the disturbance of the hole wall ground due to the drilling mud. In order to overcome these drawbacks, a self-boring method, which is a hollow excavation method, has been developed (for example, Japanese Patent No. 1223556: a device for measuring the strength and deformation characteristics of soil using a boring hole wall). However, the main purpose of this development was to obtain more accurate ground information, so it required advanced operation techniques such as suppressing changes in ground pressure as much as possible, and it was difficult to apply it in general ground surveys. Since it is a device, it has not spread.

On the other hand, the method of performing the shear test while pressurizing the hole wall has been used as a method for obtaining ground information on rubble-like ground where it is difficult to collect a sample without disturbing the ground.
However, in the collapsible ground, there are cases where the cell for shear test cannot be inserted after drilling. As with the horizontal loading test in the hole, the self-boring method has been developed, but it has a complicated mechanism and advanced operation. Since it is necessary, it has not become popular.

[0005]

The present invention is capable of reliably conducting tests on collapsible ground rather than obtaining highly accurate ground information, and is academically high in view of such problems. Evaluation is not possible, but it was done by making it possible to easily obtain the ground information with the accuracy required in design practice.

That is, in the test method of the present invention, at the time of boring of the ground, a hole wall collapse preventing hole connecting a hole wall pressurizing pipe that bulges in the radial direction at the same time is connected to the lower end, and the hole is kept at a predetermined depth. After stopping, the hole wall pressurizing pipe is expanded and brought into close contact with the hole wall to perform a horizontal load test in the hole, and the hole wall pressurizing pipe is further brought into contact with the hole wall pressurizing pipe. This is a hole loading test method characterized by conducting a friction / shear test by applying a pulling force to the.

Further, in the test apparatus of the present invention, a cutting shoe is provided at the lower end, a hole wall pressing portion having a plurality of axial slits formed in the circumferential direction is provided on the outer peripheral surface, and a drill bit is provided inside the lower end portion. A hole-retaining pipe that is rotatably attached and an upper hole-retaining pipe that is loosely connected to the lower pipe, and a hole-retaining pipe that connects the hole-retaining and load-transmitting pipe to the lower end. ,
A hole-piercing rod that is inserted into the hole-preserving tube and the hole-preserving / load transmitting tube, and the tip of the rod is detachably connected to the boring bit; A pressure cell that presses the hole wall pressure portion of the lower hole holding pipe from the inside to bring the pressure portion into close contact with the hole wall, and a connecting member with the lower hole holding pipe is connected to the lower hole holding pipe. And a connecting member for connecting to the upper hole holding pipe, and a connecting member for connecting the lower hole holding pipe and a connecting member for connecting the upper hole holding pipe. It is a functional hole-holding pipe type hole loading test device, characterized in that it comprises a pressure measuring device with an axial load meter attached between the pressure measuring device and the upper part of the pressure measuring device. And a tapered surface of the tapered shaft piston that moves up and down inside the pressure measuring device as a connecting member with the lower hole holding pipe. It is preferable to use an inwardly biased shear key member in which the tip portion loosely fits in the key groove formed on the inner surfaces of the upper and lower retaining tubes by protruding in the radial direction when engaged. is there.

The device of the present invention is of a hollow excavation type in order to reliably carry out an in-hole test even on collapsible ground. And unlike the conventional method, the main purpose is to quickly test without collapsing while allowing for subtle ground disturbances such as release of ground pressure. Insert it into the ground,
By pulling up the drilling rod, which is a drilling tool, and then inserting and setting a pressure cell or other pressure measuring device into the hole-holding tube, all the problems due to hole wall collapse are solved. That is, according to the present invention, as shown in FIG.
A reaction force projection (2) is provided inside the lower part of the hole, a bit (4) is provided at the tip of the drilling rod (3), and a rotary projection (5) for pulling the hole-holding pipe is attached above the bit (4). Allows to draw the hole-holding pipe while digging or digging ahead of the bit,
In addition, the protrusions have a rotation-sliding function so that the hole-preserving tube does not rotate during rotary drilling, so that the hole-preserving tube can be installed reliably.

Next, in order to allow the hole-holding tube to easily expand in the hole diameter direction at the test position, several slits (6) are formed in the axial direction on the outer peripheral surface of the hole-holding tube, and the hole-holding tube is easily deformed. Thus, the notches (7) are provided at the upper and lower parts of the slit. A pressure cell (8) that expands in the diametrical direction is inserted into the hole-holding tube, and a horizontal loading test is performed at the slit portion so that ground information can be obtained. The pressurization and the change of the diameter can be carried out by a pressurization control / measurement recording device (not shown) of a commonly used horizontal loading test device in a hole. Further, the shear strength of the ground can be obtained from a shear test in which the above-mentioned pressure cell is inserted into the hole-holding pipe and the hole-holding pipe is pulled up while applying pressure equivalent to the ground pressure. Furthermore, it is possible to obtain the friction angle and the adhesive force of the ground by performing a shear test while sequentially changing the applied pressure, but if the outer surface of the slit of the hole-holding pipe is slippery, the slip strength will be obtained instead of the strength characteristics of the ground. Therefore, if necessary, an uneven portion (9) is provided on the outer surface so as not to slip.

The pulling force of the hole-holding pipe can be measured by a jack (not shown) on the ground and measured by a load meter. With this method, the pulling force before pressurizing the shear test is measured to determine its own weight and hole-holding force. It is necessary to measure and correct the friction in the whole underground part of the pipe. In this method, the sameness between the test and the friction measurement in advance may become a problem, so a stress measuring section (11) by sticking a strain gauge or the like is provided above the slit section (10) if necessary. In this case, a work-related problem is that a secondary work such as protection with a special sheath is required for curing the signal cable (12) from the stress measuring section.

In order to further improve the measurement accuracy, as shown in FIG. 2, a load meter (13) is mounted on the upper part of the pressure cell, and a shear key (1) is installed above and below the load cell to transmit the tensile force with the hole-holding tube.
4) is provided. A shear groove (15) that matches the shear key is also provided in the hole-holding tube, and a thrust portion (16) is provided so that the pulling load of the hole-holding tube does not work between them.
In addition, a fall prevention key or the like should be attached beforehand so that the hole-holding tube will not separate during installation and removal. With this method, the amount of displacement during the shear test can be measured at the aboveground part of the rod (17) for the pressure cell, and the load is the hole retaining pipe in the shear part, the lower shear key, the load cell, the upper shear key and Since it is transmitted through the hole-holding pipe to the ground, no load is applied to the rod, which improves the shear strain measurement accuracy.

The hole drilling bit for medium excavation depends on the type of the target ground, but a bit smaller than the outer diameter of the hole retaining pipe or a little larger for hard soil will be set. The bit cannot pass through the hole-holding pipe because of the relationship with the wall thickness. Therefore, when setting the hole-holding tube, a bit is attached in advance to make a hole, and at the time of the test, the rod is separated and pulled up at the upper part of the rotary protrusion, and after the test is completed, the rod is re-inserted and drilled to the next depth. However, with this method, it is difficult to select and replace the bit that corresponds to the change in the ground, so by adopting a variable hole diameter bit that automatically changes the drilling diameter according to the hardness of the ground, all of the excavating tools are raised. It will be possible. In addition, this method can also be used in combination with standard penetration tests and other in-situ tests at the hole bottom of the hole-retaining pipe, thus broadening the practical application range.

[0013]

According to the present invention, it becomes possible to reliably test even the ground which cannot be measured by the pre-boring method which is now generalized due to the collapse of the hole wall. Further, when compared with the self-boring type, which has been conventionally performed as a special test, the equipment is lightweight, and there is a great merit that work can be performed without depending on a specific operator. Furthermore, since it is now possible to perform tests such as a standard penetration test at the bottom of the hole, a horizontal loading test in the hole, and a shear test in the hole, it is useful for shortening the process and reducing the investigation cost.

[0014]

EXAMPLES Examples of the present invention will be described below. As shown in FIG. 3, the device of the present invention is connected to the lower end of the hole retaining pipe (1) to transmit the loading pressure and the shearing force to the wall of the boring hole, and the hole retaining / load transfer pipe having the bit attached to the lower end. When,
Hole retaining pipe and hole retaining / load transmitting pipe that can be inserted into and recovered from the hole shown in Fig. 4 to insert the retaining hole / load transmitting pipe into a predetermined search hole by transmitting rotational force and thrust to the bit. While applying a loading pressure to the drilling rod (3) that is a drilling tool to pull the hole-holding pipe and the boring hole wall shown in FIGS. Consists of a measuring device.

The structure and function of the hole- holding / load-transferring pipe shown in FIG . 3 is a hole- holding / load-transferring pipe (100) which is an upper hole-holding pipe connected to the hole-holding pipe (1) with a screw. Perforated tube (2
3), and the shear keys (14a) (14b) and the hole-holding / load-transmitting pipes (14a) (14b) provided above and below the load meter (13) shown in FIG. 6 at the lower end of the hole-holding pipe (23) with an upper shear groove. 10
0) the lower keyhole pipe connected by the drop prevention pin (24) of the thrust part (16) that can freely expand and contract in the axial direction to facilitate the connection with the shear key grooves (15a) (15b). It is composed of a hole-holding pipe with a lower shear groove (25) and a cutting shoe (18) connected to the lower end of the hole-holding pipe with a lower shear groove (25) by a screw.

In the hole-holding pipe with upper shear groove (23), the pulling force applied to the hole-holding pipe (1) by a jack on the ground (not shown) is shown in FIG. 13) The shear key (1
4a) is provided with a shear key groove (15a). The hole holding tube with lower shear groove (25) has a load cell (1
The shear key (14b) of the pressure measuring device shown in FIG. 6 for transmitting the pulling force from the hole holding pipe (1) transmitted to 3) to the hole holding pipe with lower shear groove (25) is engaged. A shear key groove (15b) and a plurality of slits (6) in the axial direction for facilitating diametrical expansion accompanying expansion of the pressure cell (8) of the pressure measuring device shown in FIG. Notches (7a) and (7b) are provided in the upper and lower portions of the hole, and a concave-convex portion (9) is provided on the outer peripheral surface of the portion in close contact with the hole wall to prevent slippage with the ground. There is. Figure 5
As shown in FIG. 5, a fixed key (19) for mounting the bit (4) on the cutting shoe (18) so as to block the rotational force of the drilling rod (3) and transmit only the thrust, a rotary sliding member (20), A bit joint (22) is attached.

The hole-holding pipe with upper shear groove (23) and the hole-holding pipe with lower shear groove (2) of the hole-holding / load-transferring pipe (100).
5) and the cutting shoe (18) transmit the thrust transmitted to the cutting shoe (18) by the drilling rod (3) to the upper hole retaining pipe (1) at the time of drilling / inserting, and at the same time collapse the hole wall. It also plays the role of a retaining tube that prevents Further, the cutting shoe (18) prevents the circulating water supplied to the bit (4) from flowing out to the outside of the hole retaining pipe during drilling. Also, the notch (7) at the upper and lower parts of the slit (10) which is the hole wall pressurizing part of the hole retaining pipe (25) with the lower shear groove.
The unevenness processed portion (9) excluding a) and (7b) is brought into close contact with the hole wall by the pressure cell (8) of the pressure measuring device shown in FIG. 6 to reduce the pressure applied to the hole wall during the load test. During the shear test, it becomes a frictional resistance generating portion of the hole wall due to the pulling force of the hole retaining pipe (1). Thrust part (1) for connecting the hole holding pipe with upper shear groove (23) and the hole holding pipe with lower shear groove (25)
6) is the upper and lower shear key grooves (1
5a) and (15b), which are mounted by the shear keys (14a) and (14b) of the pressure measuring device shown in FIG.
In 3), the frictional resistance generated in the uneven processed portion (9) by pulling up the hole holding tube (1) is surely transmitted.

[0018]Structure and function of the drilled rod in Fig. 4 The drilling rod (3) is fixed to the cutting shoe (18).
With key to transmit rotational force and thrust to the fixed bit (4)
Has a coupling (21) at the lower end. And with key
The coupling (21) to the tip of the drill rod (3)
Then, insert it into the retention tube (1), and insert the cutting shoe (1
Bit join at the upper end of the bit (4) fixed to 8)
Rotating force on the bit by inserting it into the gutter (22) and connecting it
And transmit thrust. Rotation added to the drilling rod (3)
The force and thrust are given by a drilling device on the ground not shown.
To be

[0019]Configuration and function of the pressure measurement device of FIG. The pressurization measuring device is shown in FIG.
5) The uneven processed portion (9) is expanded and brought into close contact with the hole wall.
Accompanying the lifting of the pressure cell (8) and the holding tube (1)
Frictional force generated on the hole wall in contact with the concave and convex parts (9)
It is comprised by the load cell (13) which measures. Pressurized
(8) is an expansion membrane solid at both ends of the pressure cell core pipe (38).
Fixed cylindrical expansion membrane (36) with fixed ring (37)
The pressure cell between the pressure cell core pipe (38) and the expansion membrane.
It is expanded by the pressurized fluid fed through the circuit (39).
The tension membrane (36) is expanded. Send to pressurized liquid circuit (39)
Connect the pressurized fluid to the pressurized hose joint (29)
Shown connected to the other end of the pressure hose (33)
Not supplied from above-ground pressure equipment.

Above and below the load cell (13), the load cell (13) is attached to the shear key grooves (15a) (15b) of the upper shear groove holding tube (23) and the lower shear groove holding tube (25). Shear key operation (14a) (14b) for mounting the), and a shear key operation in which a taper shaft piston (27) for moving the taper surface (26) engaged with the shear key from the inside downward is installed. Cylinder part (2
8) was provided inside the pressure measuring device.

In addition, shear key grooves (15a) (15) sandwiching the thrust portion (16) of the upper shear groove holding hole pipe (23) and the lower shear groove holding hole pipe (25) of the load meter (13).
The connection to b) is made by the tapered shaft piston part (27).
Shear key grooves (14a) (14b) of the shear keys (14a) (14b) extruded by the diameter change of the piston portion (27) accompanying the movement of the tapered surface (26) pushed down by the pressurized fluid supplied to the cylinder portion (28) of 15a)
It is done by meshing with (15b). The pressurized fluid to the cylinder portion (28) is supplied from a not-shown above-ground pressure device connected to the other end of the pressure hose (33) connected to the cylinder pressure hose joint (30). . As the tapered surface (26) is pushed down, the spring (32) at the lower end thereof is compressed, but the cylinder (2
8) With the depressurization of the pressurized fluid in the spring (32)
Pushes the taper shaft upwards, and at the same time, the shear keys (14a) (14b) are attached to the shear keys (14a) (14b) by the return members (31) such as ring springs and O-rings. ) (15
Remove from b).

Shear key (14a) (14
The signal cable (35) of the load meter (13) sandwiched between b) is pulled out from the cable pull-out joint (34) through the hole-holding pipe to the ground at the other end, and is connected to a measuring device (not shown) on the ground. Connected and measured.

[0023]Operating procedure 1. Keyed coupling (2
Insert the drilling tool with 1) into the hole holding pipe (1)
The cutting hole at the tip of the hole / load transfer tube (100).
Bit join at the top of the bit (4) attached to the window
(22).

2. The rotation / thrust of the drilling tool for drilling / inserting the hole-holding pipe (1) and the hole-holding / load transfer pipe (100) connected to the lower end of the hole-holding pipe (1) in a predetermined search are illustrated. Not added by aboveground boring equipment.

3. The circulating water that is supplied around the bit at the time of drilling / inserting to cool the bit and remove cutting soil is supplied from the circulating water pump (not shown) in the inner space of the drilling rod (3) or the hole retaining pipe. It is supplied from the inner space of (1), and the inner space of the hole-holding pipe (1) (when circulating water is sent from the inner space of the boring rod (3)) or the inner space of the rod (the hole-maintaining pipe (1 ) When circulating water is sent from the inner space), it is discharged to above ground.

4. After installing the hole-preserving pipe (1) and the hole-preserving / load-transmitting pipe (100) connected to the lower end of the hole-preserving pipe (1) in a predetermined search, the drilling tools are separated from the bit joint (22) and placed on the ground. Pull up.

5. The pressure measuring device is connected to the insertion rod (17) and inserted into the hole holding tube (1).

6. The shear key (1
4a) (14b) with shear key grooves (15a) (15b)
The load meter (13) to the hole and load transfer tube (10).
0).

7. A pressurizing cell pressurizing device (not shown) sends a pressurized fluid to the pressurizing cell (8) of the pressurizing and measuring device, expands it at a predetermined pressure, and causes the lower shear groove holding pipe (25) to The uneven processed portion (9) is brought into close contact with the hole wall, and further pressure is applied stepwise or at a constant injection amount. At this time, the injection pressure of the pressurized fluid and the injection amount are measured by a measuring mechanism (not shown) of a pressurizing cell pressurizing device on the ground.

8. In the shear test on the hole wall, after the uneven portion (9) of the lower shear grooved hole-preserving tube (25) was brought into close contact with the hole wall with a predetermined pressure, the above-mentioned ground portion not shown was protected. Perforated tube (1)
The hole-holding pipe (1) is pulled up by the pulling device, and the pulling load detected by the load meter (13) of the pressure measuring device during the pulling process is measured by a measuring device (not shown) on the ground. At this time, a displacement measuring device (not shown) at the upper end of the insertion rod (17) lifts the insertion rod (17) (the axial movement amount of the concave-convex processed portion (9) of the lower shear grooved hole retaining pipe (25)). Equivalent to) is measured.

9. The measured pressure cell pressure, the amount of fluid injected into the pressure cell, the lifting load of the uneven processing portion (9) of the hole holding pipe with a lower shear groove (25), and the displacement amount in the coaxial direction are corrected by the following corrections. Find the physical properties of the wall. Pressure applied to hole wall: Ph Ph = Pcmv−Piv Ph: Pressure applied to hole wall Pcmv: Pressure applied to pressurizing cell (injection amount V of liquid injected into pressurizing cell at the time of pressurizing Pcmv) Piv: Pressure necessary for expansion of the expansion film of the pressure cell and the concave / convex portion when the liquid is injected V. Friction resistance on the outer peripheral surface of the convex / concave portion at the pressure Ph applied to the hole wall: τ τ = T / A τ: irregularity Maximum value of frictional resistance of the outer peripheral surface of the processed portion T: Maximum value of pulling load of the uneven processed portion A: Outer peripheral area of the uneven processed portion

10. FIG. 8 shows an example of the test result by the device of the present invention.

[0033]

According to the existing in-situ loading test and friction / shear test techniques for boring hole walls, With the method of setting the probe after boring, it is difficult to apply it to collapsible ground because the ground pressure is released, and the hole wall ground is easily disturbed by scouring of the hole wall due to circulating fluid. 2. The self-boring method requires advanced drilling and sample manipulation technology, which reduces work efficiency. There is a problem such as.

This device has a mechanism in which the diameter of the probe is made slightly smaller than the diameter of the drilling bit in order to facilitate insertion of the probe. The following effects can be expected by adopting a mechanism that integrates the test equipment installed in the equipment with the hole-holding pipe and drilling tools. 1. By processing the circulating fluid in the hole-holding pipe, there is less disturbance due to scouring of the hole wall, and more accurate ground information can be obtained compared to the conventional pre-boring method. 2. Since it is possible to insert a cell and a hole-holding pipe at the same time as drilling, it is possible to obtain ground information with sufficient accuracy in design practice even on rubble ground or collapsible ground where it is difficult to sample without disturbing. 3. By reducing the peripheral resistance due to the insertion of cells, the boring device can adopt a normal surveying device and continuously perform drilling and testing, which is equivalent to the conventional pre-boring system. The above work efficiency can be expected.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a state in which a hole-preserving tube, a test apparatus portion integrated with the hole-preserving tube, and a hole making tool according to the present invention are mounted.

FIG. 2 is an explanatory view showing a state at the time of a test in which a pressurization measuring device is installed in the hole retaining tube in the present invention.

FIG. 3 is a side view showing a cross section of a main part of the hole / load transfer tube according to the embodiment of the present invention.

FIG. 4 is a side sectional view of a drilling tool according to an embodiment of the present invention.

FIG. 5 is a side view showing a cross section of a main part of a combination of the hole-retaining / load-transmitting pipe and the drilling tool in the embodiment of the present invention.

6A and 6B show a pressure measuring device according to an embodiment of the present invention, in which FIG. 6A is a side sectional view of the device, and FIG. 6B is an explanatory diagram showing a route of a signal cable of a load meter.

FIG. 7 is a side view showing a cross section of a main part of a state in which a hole-retaining / load-transmitting tube and a pressure measuring device are combined in the embodiment of the present invention.

FIG. 8 shows an example of test results using the device of the present invention, and is a curve showing the relationship between frictional strength and shear displacement.

[Explanation of symbols]

1 retention tube 3 Drilling rod 4 bits 6 slits 8 pressure cell 9 Uneven processing part 13 load cell 14a, 14b Shear key 15a, 15b Shear key groove 16 Thrust part 17 Insert rod 18 cutting shoes 23 Hole retaining pipe with upper shear groove 25 Hole retaining tube with lower shear groove 26 Tapered surface 27 Tapered shaft piston part 31 Return material (ring spring or O-ring) 32 spring 33 Pressure hose 34 Cable Draw Joint 35 signal cable 36 Inflatable membrane 37 Expansion membrane fixing ring 38 Pressurized cell core pipe 39 Pressurized liquid circuit

Continuation of the front page (56) Reference JP 54-75811 (JP, A) JP 55-23257 (JP, A) JP 63-150639 (JP, A) JP 4-306393 (JP , A) JP-A-9-72184 (JP, A) JP-A-9-291779 (JP, A) JP-B-47-44930 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB) Name) E02D 1/02 G01N 3/00

Claims (3)

(57) [Claims] 1. A hole-holding pipe having a plurality of axial slits formed in the circumferential direction on the outer peripheral surface thereof, and further provided with a protrusion on the inner side of the lower end, to excavate the inside of a hole-holding pipe in an open state. However, the thrust of the boring rod is applied to this protrusion to pull the hole-holding pipe into the ground to a predetermined depth, and after collecting the rod or rod and bit to the ground, a pressurizing device that expands radially into the hole-holding pipe is installed. An in-hole load testing device, characterized in that the hole wall pressurizing portion of the hole retaining tube is expanded to apply a pulling force to the hole retaining tube on the ground. 2. A cutting shoe is provided at the lower end, a hole wall pressing portion having a plurality of axial slits formed in the circumferential direction is provided on the outer peripheral surface, and a drill bit is rotatably attached inside the lower end. Lower hole pipe and upper hole pipe loosely connected to the lower hole, load hole holding pipe, hole hole connecting the hole hole and load pipe to the lower end, and the hole hole pipe and Insert into the hole-holding / load-transmitting pipe, detachably connect the tip of the hole-drilling bit to the drilling bit, and transmit the thrust and rotational force to the drilling bit to drill the hole in the ground for hole-loading transmission. A drilling rod that installs the pipe at a predetermined depth, and an insertion rod that inserts the pipe into the hole-holding pipe and the hole-holding / load-transfer pipe. Providing a pressure cell that bulges the pressure part and makes it closely contact with the hole wall, and engages with the lower hole retaining tube An existing lower connecting member is provided, an upper connecting member that can be engaged with the upper hole retaining pipe is provided, and an axial load meter is attached between the lower connecting member installation portion and the upper connecting member installation portion. A functional hole-retaining pipe type hole loading test device comprising a pressure measuring device. 3. An upper retaining hole that projects upward in a radial direction by engaging an upper connecting member and a lower connecting member of a pressure measuring device with a tapered surface of a tapered shaft piston that moves up and down inside the pressure measuring device. 3. The functional hole-holding pipe type hole-loading test device according to claim 2, which is a shear key member in which a tip portion is loosely fitted in a key groove formed on the inner surface of the pipe and the inner surface of the lower hole-holding pipe and is biased inward. .