JP2001090468A - Sampling apparatus for use in geological boring survey - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sampling apparatus which reduces the contact frictional resistance of an intertruss bracing ring with respect to a peripheral surface of a sampling cylinder. SOLUTION: There is provided a sampling apparatus for use in a geological boring survey, which is constructed by connecting an external cylinder 12 to a test drill via a connecting tube so as to be rotatively driven, fitting a sampling cylinder 6 into the external cylinder 12, supporting an upper end of the sampling cylinder 6 by means of the external cylinder 12, and attaching an intertruss bracing ring 31 which supports a lower end of the sampling cylinder 6, onto an inside at a lower end of the external cylinder 12. In the thus constructed sampling apparatus, the intertruss bracing ring 31 has supporting projections 31a which each make sliding contact with a peripheral surface of the sampling cylinder 6, on its internal peripheral surface at required intervals in the circumferential direction. Further, pressure water flowing gaps 31b are defined by the projections 31a and the peripheral surface of the sampling cylinder 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a geological boring survey for examining the geological condition of underground clayey and silt layers and the like. The present invention relates to a sample collecting apparatus described in FIG.

[0002]

2. Description of the Related Art In a general geological boring survey, as shown in FIG. 6, a connecting pipe 3 is successively added to a borehole 4, and an apparatus main body 2 of a sampling apparatus connected to the lowermost connecting pipe 3 is excavated. After being inserted into the hole 1, the outer cylinder of the apparatus main body 2 is driven to rotate to excavate the formation, thereby collecting a sample in the sample cylinder, which is the inner cylinder inserted into the outer cylinder. Has lifted the apparatus main body 2 to the ground in the reverse order, and has taken out the sample 5 as shown in FIG.

In the conventional sampling apparatus, the upper end of the sampling cylinder is supported by the outer cylinder via a bearing, but the lower end is not supported at all. Is transmitted to the upper end of the sampling tube, the lower portion of the sampling tube vibrates with the upper end as a fulcrum, and the sample 5 collected in the sampling tube may be disturbed. It was not known whether the layers 5a to 5e remained underground.

[0004] In order to prevent the sample collection tube from vibrating as described above, the applicant of the present invention has a sample in which a steady ring is mounted inside the lower end of the outer tube to support the lower end of the sample collection tube. A sampling tube support was previously proposed. According to this steady ring, even when vibration due to the rotational driving force of the outer cylinder is transmitted to the upper end of the sampling cylinder during excavation of the soil, the lower part of the sampling cylinder is supported by the ring, so that the sample is removed. There is no possibility that the lower part of the sampling cylinder swings with its upper end as a fulcrum.

[0005]

However, in the above-mentioned conventional steady rest ring, the ring itself is fixed to the outer cylinder side, but the entire circumferential area of the inner peripheral face of the ring contacts the outer peripheral face of the sample collection cylinder. Therefore, the friction resistance of the steady ring against the outer peripheral surface of the sample collecting cylinder is large, and the sample collecting cylinder may rotate together with the outer cylinder during rotation. However, when the sample collecting cylinders rotate together, the sample collected in the sample collecting cylinder may be distorted due to twisting or the like.

The present invention has been made in view of the above problems, and has as its object to provide a sample collecting apparatus in which the contact friction resistance of the steady rest ring with respect to the outer peripheral surface of the sample collecting cylinder is minimized.

[0007]

According to a first aspect of the present invention, there is provided a sample collecting apparatus for a geological boring survey, in which a drilling outer cylinder is rotatably connected to a borehole through a connecting pipe. The sampling tube 6 is inserted concentrically into the tube 12, the upper end of the sampling tube 6 is supported by the outer tube 12 via a bearing 26, and the sample is inserted inside the lower end of the outer tube 12. In a sample collecting device in a geological boring survey in which a steady ring 31 for supporting a lower end portion of the sampling cylinder 6 is attached, a support ring that slides on the inner peripheral surface of the steady ring 31 and the outer peripheral surface of the sampling cylinder 6 is provided. Convex part 31a
Are formed at predetermined intervals in the circumferential direction, and these convex portions 31a are formed.
It is characterized in that a gap 31b for passing pressure water is formed between each other and the outer peripheral surface of the sampling tube 6.

According to a second aspect of the present invention, in the sample collecting apparatus for geological boring survey according to the first aspect, each of the supporting projections 31a of the steady rest ring 31 is provided with a tip supporting surface a that is in contact with the outer peripheral surface of the sample collecting cylinder 6. The upper and lower ends b are each chamfered.

[0009]

1 and 2 are a cross-sectional view and a vertical cross-sectional view showing, on an enlarged scale, an attached state of a steady rest ring 31 provided in a sample collecting apparatus according to the present invention, and FIGS. FIG. 3 is a longitudinal sectional view of each of the sample collecting devices. The steady ring 31 is disposed between the sampling cylinder 6 and the excavating outer cylinder 12 which is fitted concentrically to the sampling cylinder 6. On the peripheral surface, for example, five supporting protrusions 31a that are in sliding contact with the outer peripheral surface of the sample collection tube 6 are formed at regular intervals in the circumferential direction. And a gap 31b for passing pressure water is formed. The outer periphery of the steady ring 31 is locked to a step 34 inside the lower end portion of the outer cylinder 12 for excavation, and receives vibrations caused by the rotational driving force of the outer cylinder 12 so that the outer periphery of the lower part of the sample collection cylinder 6 is exposed. The cylinder 12 is prevented from swinging about its upper end as a fulcrum.

Each support projection 3 of the steady ring 31
1a is formed into a gentle concave surface corresponding to the convex curved surface of the outer peripheral surface of the sampling tube 6, but has a circumferential width in contact with the outer peripheral surface of the sampling tube 6 as shown in FIG. 2 and the upper and lower ends of the front end support surface a are shown in FIG.
Since the inclined surface b is formed by chamfering as shown in FIG. 7, the length in the axial direction is also reduced, and therefore, the co-rotation of the sampling tube 6 when the outer tube 12 is driven to rotate can be reliably avoided. In addition, since the upper and lower ends c and c of the distal end support surface a of each support projection 31a are chamfered, the operation of fitting the steady rest ring 31 to the sample collection cylinder 6 can be easily performed.

The schematic structure of the sampler is shown in FIG.
As shown in the figure, the apparatus main body 13 includes a connecting pipe 10 connected to the main body 13 in order.
Is provided. In FIG. 5A, reference numeral 4 denotes a borehole for vertically supporting the connecting pipe 10 and sending it out into the ground.

The structure of the sample collecting device will be described in detail. As shown in FIG. 3, a connecting portion 17 for connecting to the connecting pipe 10 is provided at the upper end of a cylindrical device main body 13 and is slidable up and down. A passage 14 in which a spool 15 serving as a valve body is provided is formed. The passage 14 is provided in the conduit 10a of the connecting portion 10.
And a second pressure water supply passage 21 communicating with the inside of the outer cylinder 12 integrally connected to the upper end of the apparatus main body 13. The first pressure water supply passage 20 communicates with the spool 15 and the second pressure water supply. The upper end of the passage 21 is provided with communication holes 22 and 23 for communicating the first and second pressure water supply passages 20 and 21 with each other when the spool 15 swings upward (see FIG. 4). .

An outer cylinder 12 is provided on the lower surface of the upper end of the apparatus body 13.
The idler block 27 is freely rotatably mounted on the central shaft 25 protruding concentrically with the thrust and radial bearings 26 by loosening the thrust and radial bearings 26.
0 is connected continuously. Reference numeral 28 denotes a retaining nut for a free-rotating block. Further, the upper end of the connecting pin 16 is vertically slidably fitted into a hole which is displaced in the circumferential direction from the second pressure water supply passage 21 at the upper end of the apparatus main body 13 and is formed in parallel with the circumferential direction. The upper end of 16 is connected to the spool 15 via a connecting rod, and the lower end is engaged with the engaging hole 29 of the idler block 17, thereby preventing the sample collection tube 6 from rotating.

The sampling tube 6 has its tip edge 6a projecting slightly below the outer tube 12 so as to hit the soil W before the outer tube 12. The device body 1
An air vent hole 33 with a check valve 32 for releasing the air inside the sampling tube 6 to the outside is provided at the upper end of the sample shaft 3 so as to communicate with the hollow portion a of the central shaft 25.

In the above configuration, the conduit 10 of the connecting pipe 10
a, pressure water is pressure-fed from the ground at the time of sampling, and this pressure water passes through the first pressure water supply passage 20 of the apparatus main body 13, and as shown in FIG.
5 is pushed upward, the connection holes 22 and 23 are aligned, and the first and second pressure water supply passages 20 and 21 are switched to the communicating state.
Is supplied to the inside of the outer cylinder 12 through the nozzle, and is ejected to the outside from between the outer cylinder 12 and the sample collection cylinder 6 to promote the excavation work at the time of sample collection. At the same time, the connection pin 16 is moved upward by the upward movement of the spool 15, disengages from the engagement hole 29 of the free rotation block 27, and the connection state between the sample collection cylinder 6 and the outer cylinder 12 is released.

The sampling method will be described. As shown in FIG. 5A, when the chuck cylinder 35 provided on the borehole drill 4 is lifted by the hydraulic cylinder 36, it is connected to the inside of the chuck cylinder 35. The pipe 10 is inserted, and the apparatus main body 13 is connected to the lowermost connection pipe 10 in the same procedure as the connection procedure between the connection pipes 10 described above (see FIG. 3).

Next, the connecting pipe 10 is lowered so that the apparatus body 1
3 is inserted into the borehole 1, and the connecting pipes 10 are sequentially added until the apparatus main body 13 reaches the sampling position. Then, at the time when the depth reaches a predetermined depth and the leading edge 6a of the sampling tube 6 in the apparatus main body 13 bites into the soil W to be sampled, FIG.
As shown in FIG.
Then, the hydraulic pump 38 is operated to introduce the pressurized water into the apparatus main body 13 through the conduit 10a of the connecting pipe 10.

As a result, the spool 15 moves upward to release the connection between the sampling tube 6 and the outer tube 12 by the connecting pin 16, and the motor 39 of the borehole drill 4 moves the outer tube 12 through the connection pipe 10. By being driven to rotate, the soil W to be sampled is excavated, and at the same time, pressurized water is ejected to the outside from between the sampling cylinder 6 and the outer cylinder 12 for excavation, thereby facilitating the excavation work. At this time,
Vibration caused by the rotational driving force of the outer cylinder 12 for excavation causes
The lower end of the sampling tube 6 is supported by the steady ring 31 provided at the lower end of the outer tube 12, so that the lower portion of the sampling tube 6 swings about the upper end as a fulcrum. It doesn't move.

Further, since the tip edge 6a of the sample collecting tube 6 is in contact with the soil W to be sampled, the sample collecting tube 6 does not rotate but the body 13 and the outer tube 12 for excavation rotate. It is pushed into the collected soil W. In particular, in this case, in the steady ring 31, the distal end supporting surface a of the supporting convex portion 31 a provided at regular intervals in the circumferential direction on the inner peripheral surface thereof is in sliding contact with the outer peripheral surface of the sample collection tube 6. Since the contact frictional resistance of the ring 31 to the outer peripheral surface of the sampling tube 6 is small, the rotation of the outer tube 12 does not rotate the sampling tube 6.

When a predetermined amount of the sample 7 has been collected in the sampling tube 6, the pushing by the borehole machine 4 and the supply of the pressurized water are stopped, and the connecting pipe 10 is sequentially pulled up. Take out sample 7 from inside. In this case, since the sampling tube 6 does not rotate, the sample 7 is not disturbed as shown in FIG. 5 (B), and it is necessary to accurately detect a state in which the formations 7a to 7d remain in the ground. Can be.

[0021]

According to the first aspect of the present invention, on the inner peripheral surface of the steady rest ring, supporting projections which are in sliding contact with the outer peripheral surface of the sample collecting cylinder are formed at required intervals in the circumferential direction. Since the gap for pressure water passage is formed between each other and the outer peripheral surface of the sampling tube, the contact surface of the steady rest ring contacting the outer peripheral surface of the sampling tube is reduced, and the The contact friction resistance of the steady rest ring with respect to the outer peripheral surface is reduced, and the co-rotation of the sampling tube due to the rotation of the excavating outer tube can be avoided.

According to the second aspect of the present invention, since the upper and lower ends of the front end support surfaces of the respective support projections are chamfered, the contact surface of the steady rest ring which comes into contact with the outer peripheral surface of the sample collection cylinder is further increased. In addition to being able to reduce the number, it is possible to easily perform the fitting operation of the steady rest ring to the sampling tube.

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional view showing a mounting state of a steady ring mounted on a sample collecting apparatus according to the present invention,
-It is an X-ray enlarged sectional view.

FIG. 2 is a sectional view taken along line YY of FIG.

FIG. 3 is a longitudinal sectional view of the sample collecting device.

FIG. 4 is a longitudinal sectional view showing an operation state of the sample collection device.

FIG. 5A is an overall schematic diagram showing a use state of a sample collecting device, and FIG. 5B is an enlarged perspective view of a sample collected by the sample collecting device.

FIG. 6 is a schematic explanatory view showing a use state of a conventional example.

FIG. 7 is a view showing a stacked state of samples collected by the conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drilling hole 4 Drilling machine 6 Sampling cylinder 7 Sample 10 Connecting pipe 12 Outer cylinder for excavation 31 Sway ring 31a Supporting convex part a Tip supporting surface of supporting convex part b Chamfered part 31b Air gap for pressure water passage

Claims (2)

[Claims] An excavating outer cylinder is rotatably connected to a borehole through a connecting pipe, and a sampling tube is concentrically inserted into the outer cylinder, and an upper end of the sampling tube is supported by a bearing. Along with supporting the outer cylinder through, and inside the lower end of the outer cylinder,
In a sample collecting device in a geological boring survey in which a steady ring is mounted to support a lower end portion of a sample collecting tube, a support convex portion which slides on an inner peripheral surface of the steady rest ring and an outer peripheral surface of the sample collecting tube is provided. A sampling device for geological drilling, characterized in that a plurality is formed at required intervals in the circumferential direction, and a gap for pressurized water passage is formed between these convex portions and the outer peripheral surface of the sampling tube. . 2. The geological boring according to claim 1, wherein each of the supporting projections of the steady rest ring has chamfered upper and lower ends of a tip support surface in contact with the outer peripheral surface of the sample collection cylinder. Sampling equipment for surveys.