JPH11100835A - Sampler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sampler that can positively extract a sample of the weak ground without needing a large-scare attachment. SOLUTION: An intermediate tube 34 is arranged at the lower part of a core tube 16, and both tubes are connected to each other by a flexible tube 38. The flexible tube 38 is previously twisted. After extracting a sample, a piston 28 connected to the core tube 16 is driven to move the core tube 16 up. When the core tube 16 is moved up, a clearance is formed between the core tube 16 and the intermediate tube 34, so that the previously twisted flexible tube 38 gets into this clearance and is contracted in diameter to close the lower end part of the core tube 16, and the sample in the core tube 16 is held by the diameter-contracted flexible tube 38.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sampler for collecting a geological sample, and more particularly to a sampler for collecting sediment distributed in the ground using a borehole or the like.

[0002]

2. Description of the Related Art When sand or mud is on the seabed or riverbed and contains a large amount of water, the sample lacks viscosity, and even if it can be held in the ground by a conventional sampler, the sample falls off when pulled up. I often did. Therefore, various methods have been devised to prevent the sample from falling off when the sampler is pulled up. For example, a method of injecting a chemical such as calcium chloride or silicon soda into the cutting edge after the sample is secured to cure the cutting edge (chemical solution injection method), or sending compressed air to the cutting edge to partially unsaturate the cutting edge A method of forming an appropriate surface and giving apparent adhesion by surface tension (air chamber method), injecting a freezing gas into the cutting edge to freeze the lower part of the sample, or freeze the formation before sampling. In addition, there is a method of sampling frozen soil (freezing method).

[0003] However, the sampler according to these methods requires a device for injecting a chemical solution, a device for freezing the formation, and the like, and has a disadvantage that the entire device becomes large. In addition, samplers using these methods require a complicated and time-consuming sample collection operation.
There was a drawback that the sampling rate was poor. For this reason,
It has been desired to provide a sampler that can reliably collect a sample with a simpler mechanism.

[0004] The sampler disclosed in Japanese Patent Publication No. 56-31536 has been developed from this viewpoint.
A flexible tube is provided at the cutting edge, and after the sample is collected, the flexible tube is twisted to close the lower end of the core tube and prevent the sample from falling off.

[0005]

However, the sampler disclosed in Japanese Patent Publication No. 56-31536 has a mechanism based on the frictional force between the hole wall and the outer tube. In the case of a layer in which the frictional force cannot be expected, there is a disadvantage that it does not work effectively.

The sampler disclosed in Japanese Patent Publication No. 56-31536 is a piston sampler of a type in which a core tube is pushed by force, so that when applied to a sand layer, a very large force is pushed into the sand layer. There was a disadvantage that it required. In this regard, the double core barrel type excavated sampler can easily penetrate the core tube even in the case of a sand layer, but it is necessary to send water to the tip of the bit to discharge the cuttings, and this water is In addition, there is a problem that the sample is washed away.

[0007] The present invention has been made in view of such circumstances, and has as its object to provide a sampler that can reliably sample a soft ground without requiring a large-scale auxiliary device.

[0008]

In order to achieve the above object, the present invention provides an outer tube having a bit at a lower end, an inner tube rotatably housed inside the outer tube, and an inner tube. A core tube housed inside the tube, an intermediate tube housed inside the inner tube, which is separably joined to the core tube, and a bit provided at the tip of the inner tube or the intermediate tube; A water-impervious shoe protruding from the tip of the flexible tube attached to the outer periphery of the joint between the core tube and the intermediate tube in a pre-twisted state and connecting the core tube and the intermediate tube; Moving means for moving the core tube and the intermediate tube in a direction in which the core tube and the intermediate tube are relatively separated from each other. Diameter of pre-twisted flexible tube is reduced in diameter, characterized in that for closing the lower end of the core tube.

According to the present invention, the core tube and the intermediate tube are joined in a separable state, and a flexible tube that is twisted in advance is attached to the joint. For this reason, only by moving the core tube and the intermediate tube relatively far apart, the flexible tube is reduced in diameter and the lower end of the core tube can be closed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a sampler according to the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is an overall configuration diagram of an embodiment of a sampler according to the present invention, and FIG. 2 is an enlarged view of a portion A thereof.

As shown in FIGS. 1 and 2, a sampler 10 of the present embodiment is a double core barrel type sampler, and includes an outer tube 12, an inner tube 14, and a core tube 1.
6 as a main member. The outer tube 12 is formed in a cylindrical shape, and a bit 18 is connected to a lower end thereof. A coupling head 20 is connected to the upper end of the outer tube 12, and a boring rod 22 is connected to the coupling head 20.
The outer pipe 12 obtains the rotation and the pushing load from the boring rod 22 and excavates with the bit 18 at the tip.

The inner pipe 14 is housed inside the outer pipe 12. A swivel 24 is connected to the upper end of the inner tube 14, and the swivel 24 has bearings 26, 26.
And is rotatably supported by the outer tube 12 via the. Therefore, only the outer pipe 12 rotates during excavation. The core tube 16 is housed inside the inner tube 14. A piston 28 is connected to the upper end of the core tube 16, and the piston 28 is slidably supported inside the swivel 24. Therefore, the core tube 16
When the piston 28 moves up and down, the piston 28 moves up and down. In order to prevent rotation during the sliding, a vertical groove 30 is formed on the outer periphery of the distal end of the core tube 16, and a pin 32 provided in the inner tube 14 is fitted into the vertical groove 30. ing.

An intermediate tube 34 is disposed below the core tube 16 as shown in FIG. The intermediate tube 34 is fixed to the distal end of the inner tube 14 via a fixing pin 36. When the core tube 16 descends, its ends are joined to each other, and when the core tube 16 rises, it separates. The core tube 16 and the intermediate tube 34
The outer periphery of the joint is covered with a flexible tube 38. The flexible tube 38 has an upper end fixed to the core tube 16 by an upper fixing band 40 and a lower end fixed to the intermediate tube 34 by a lower fixing band 42. The core tube 16 and the intermediate tube 34 are connected to each other via the flexible tube 38.

By the way, the intermediate tube 34 can be given a rotation by removing the fixing pin 36. Therefore, when the intermediate tube 34 is rotated (about one rotation) with the flexible tube 38 mounted, the flexible tube 38 can be twisted. Here, in a state where the core tube 16 and the intermediate tube 34 are joined to each other (the state shown in FIG. 2 and this state at the time of excavation), the flexible tube 38 It is in a state of covering the outer periphery.

However, when the core tube 16 is lifted to separate the core tube 16 from the intermediate tube 34, as shown in FIG. 4, the flexible tube 38 is caused by the twisting action given in advance. Core tube 16
And the intermediate tube 34, and the core tube 1
6 can be closed at the lower end. Core tube 16
The sample collected inside the flexible tube 3
8 holds.

A waterproof shoe 44 is slidably supported at the distal end of the intermediate tube 34. The water-impervious shoe 44 is provided so as to protrude from the tip of the bit 18, and a tip 44A is formed at the tip. The water-blocking shoe 44 is slidably supported in a shoe case 46 at the distal end of the inner tube 14, and is constantly urged downward by a spring 48 disposed in the shoe case 46. Have been. In addition, the impermeable shoe 44
May be fixed to the intermediate tube 34 or the shoe case 46.

The water-blocking shoes 44 prevent the drilling water supplied from the tip of the bit 18 from flowing into the core tube 16 by squeezing into the ground due to the pushing load supplied from the boring rod 22. Therefore, the presence of the water-blocking shoes 44 enables the sample to be collected in the core tube 16 even before the drilling water has washed out the sample even on soft ground such as sand.

Here, the water supply of the drilling water in the sampler 10 of the present embodiment is performed as follows. As shown in FIG. 1, drilling water is supplied to the sampler 10 through the inside of the boring rod 22. The drilling water supplied to the sampler 10 is first introduced into a first water supply chamber 50 formed in the coupling head 20. In the first water supply chamber 50, a valve 52 is slidably provided.
It is urged upward by a spring 54 (it is always located upward during excavation).

The drilling water introduced into the first water supply chamber 50 passes through a pipe 52A at the center of the valve 52, is led to the first water supply chamber 50, and is passed through the first water supply chamber 50 to the second water supply chamber. 56. The second water supply chamber 56 is formed above the swivel 24, and the excavation water introduced into the second water supply chamber 56 passes through a second water supply passage 58 formed in the swivel 24. 3 The water supply chamber 60 is introduced.

The third water supply chamber 60 is formed below the coupling head 20.
The drilling water introduced at 0 passes between the outer pipe 12 and the swivel 24, passes through the bottom charge hole 18 A of the bit 18 shown in FIG. Is discharged. Then, the discharged drilling water takes in the cuttings to form a hole wall and an outer pipe 1.
2 and is discharged to the ground.

The water supply of the drilling water is as described above, but it is necessary to extract water (or air) from the core tube 16 when collecting a sample. In the sampler 10 of the present embodiment, the drainage is performed as follows. A first water passage 62 communicating with the core tube 16 is formed inside the piston 28.
The water inside is first introduced into the first water channel 62. The first water passage 62 is provided with a check valve 64 so that water once introduced into the first water passage 62 cannot flow back into the core tube 16.

The water introduced into the first water passage 62 is introduced into a second water passage 66 also formed in the piston 28, and is introduced into the first drainage chamber 68 via the second water passage 66. The water introduced into the first water chamber 68 is
Is introduced into the first water supply chamber 50 through a third water passage 70 formed in the swivel 24, a fourth water passage 72 formed in the swivel 24, and a fifth water passage 74 formed in the coupling head 20.

The water introduced into the first water supply chamber 50 passes through a recess 52B formed on the outer periphery of the valve 52 and is discharged out of the sampler 10 through a drain 76 formed in the coupling head 20. Extraction of water (or air) from the core tube 16 is performed as described above.

The sampler 10 according to the present embodiment is
As described above, by reducing the diameter of the flexible tube 38 that has been twisted in advance, the sample collected in the core tube 16 is prevented from falling off. In order to reduce the diameter of the flexible tube 38, it is necessary to raise the core tube 16 and separate it from the intermediate tube 34.

The raising of the core tube 16 is performed by raising the piston 28 to which the core tube 16 is connected. The driving of the piston 28 is performed by the following mechanism. In this case, first, as shown in FIG.
The water stop ball 78 with the handle bar 78A is dropped into the bowling rod 22 from the ground. This water stop ball 7
8 falls into the first water supply chamber 50,
Block 2A. Drilling water is supplied with the pipe 52A of the valve 52 closed.

The drilling water supplied to the sampler 10 is first introduced into the first water supply chamber 50 as in the above-described excavation. However, as described above, the pipe 52A of the valve 52
Is closed, the drilling water does not flow into the first water supply chamber 50, but instead presses the valve 52 with its water pressure to move it downward. When the valve 52 moves downward, drilling water is supplied to the fifth water channel 74.

The drilling water supplied to the fifth channel 74 is
The first cylinder chamber 8 via the fourth water channel 72 and the third water channel 70
0 is introduced. Here, the first cylinder chamber 80 is
It is formed in the piston 28 and has a check valve fixing piston 82 therein. When the drilling water is supplied into the first cylinder chamber 80, the check valve fixing piston 82 is pressed by the hydraulic pressure and moves downward.
When the check valve fixing piston 82 moves downward, the lower end thereof abuts against the check valve 64 to fix the check valve 64. By fixing the check valve 64 in this way, it is possible to prevent the sample from leaking from the core tube 16.

Here, when the check valve 64 is fixed as described above, the drilling water reaches a dead end state. When such a dead end occurs, the drilling water flows out of the third water passage 70 formed in the piston 28 into the second cylinder chamber 86 via the introduction flow passage 84. The drilling water flowing into the second cylinder chamber 86 acts on the piston 28,
The piston 28 is raised by the water pressure.

As described above, the sampler 1 according to the present embodiment
At 0, the piston 28 is driven using the water supply pressure of the drilling water. The operation of the embodiment of the sampler according to the present invention configured as described above is as follows. First, the flexible tube 18 is twisted at the stage of setting before excavation. This operation is performed by the intermediate tube 3 as described above.
4 is rotated about once in the inner tube 16.

When the above setting is completed, a sample is collected. The sampling is performed in the following procedure. First, the sampler 10 is gently lowered into a borehole excavated to a predetermined sampling position. Then, the sampler 10 is installed vertically to the hole bottom. After installing sampler 10,
Boring rod 22 from the excavator installed on the ground
And a supply pressure (push load) is applied to the coupling head 20 via the. Then, at the same time, the drilling water is supplied to the sampler 10 via the boring rod 22 to start pushing.

Here, the rotation given to the coupling head 20 is transmitted only to the outer tube 12 (the inner tube 14 and the core tube 16 are not rotated).
The ground is excavated by the bit 18 and the sample standing up from the ground penetrates into the core tube 16. In addition, the drilling water that has been sent is the bottom charge hole 18A of the bit 18 or the bit 18 and the impermeable shoe 44.
And is discharged out of the sampler 10. Then, it passes between the hole wall and the outer pipe 12 together with the cuttings and is discharged to the ground.

Here, as mentioned above, the drilling water is
8 is discharged from the bottom charge hole 18A or between the bit 18 and the impermeable shoe 44. Since the inner diameter of the bit 18 is sealed by the impermeable shoe 44, the sample is washed away by the supplied drilling water. It will not be.
When the sampler 10 has penetrated to the predetermined position, the excavation operation is stopped, and the ground separation operation of the sample collected in the core tube 16 is performed while standing up from the ground. The sample separation operation is performed as follows.

First, the threaded portion of the boring rod 22 on the ground is loosened, and the water stopping ball 7 is inserted into the boring rod 22.
Drop 8 Then, the screw portion of the boring rod 22 that has been loosened again is re-tightened. The water stop ball 78 dropped into the boring rod 22 closes the pipe 52A of the valve 52 installed in the first water supply chamber 50 as shown in FIG. Water.

The drilling water sent to the sampler 10 first acts on the check valve fixing piston 82 to move the check valve fixing piston 82 downward. The moved check valve fixing piston 82 presses the check valve 64 from above, thereby preventing the sample collected in the core tube 16 from leaking. The drilling water that has caused the check valve fixing piston 82 to move downward then acts on the piston 28 to move the piston 28 upward. This piston 2
8 moves upward, the core tube 16
Moves upward, and as a result, the core tube 16 and the intermediate tube 34 separate. And this core tube 1
By separating the intermediate tube 6 and the intermediate tube 34, a gap is formed therebetween as shown in FIG.
The diameter is reduced to close the lower end of the core tube 16.

That is, by giving the torsion in advance to the flexible tube 38, a force for always shrinking works. This force is composed of a force in the circumferential direction and a force in the radial direction. When a gap is formed between the core tube 16 and the intermediate tube 34, the force that suppressed the radial force is released at once. You. As a result, the flexible tube 38
At a stretch enters this gap and reduces its diameter, and its twisting also concentrates on this part. The twisted flexible tube 38 closes the lower end of the core tube 16, separates the collected sample from the ground, holds the sample in the core tube 16, and collects the sample.

At the stage where the above operation is completed, the sampler 1
If 0 is collected on the ground, necessary samples can be collected at the same time. After collection, if the coupling head 20 side is lowered and disassembled from the bit 18, the check valve 64 and the check valve fixing piston 82 prevent the sample from flowing out on the piston 8 side. The sample can be removed in perfect form.

As described above, the sampler 1 according to the present embodiment
According to 0, sampling of soft ground such as sand and sludge can be performed without using a large-scale special device such as a chemical solution injection device or a freezing device. Further, the sampler 10 of the present embodiment is of a double core barrel type, and performs sampling while excavating by rotating the bit 18, so that sampling can be easily performed even with tight sand.

Further, since the sample holding mechanism does not rely on the frictional force between the hole wall and the outer tube as in the conventional sampler, reliable sampling can be performed even in a layer where frictional force such as sludge cannot be expected. be able to. Furthermore, since the sampler 10 of the present embodiment includes the water-blocking shoe 44 at the tip, the sampler 10 can completely block the drilling water and the sample. Therefore, it is possible to completely prevent the sample from flowing out due to the drilling water, and to collect the sample in a perfect form.

At the time of sample collection, the core tube 16
Since the upper drain hole (first water channel 62) is closed, the sample can be collected without leaking.
In addition, since a valve mechanism is used for switching between sample excavation and sample separation, consumables such as a shear pin are not required, and the economy is improved. In the present embodiment, the piston 28 operated by the water supply pressure of the drilling water is used as a means for separating the core tube 16 and the intermediate tube 34, but the means for moving the core tube 16 is not limited to this. What is necessary is just something which can move the core tube 16 along an axis.

In the present embodiment, the intermediate tube 3
4 is fixed and the two are separated by moving the core tube 16 side, but the two may be separated by moving the intermediate tube 34 side.

[0041]

As described above, according to the present invention,
It is possible to reliably collect a sample of soft ground without requiring a large-scale accessory. In addition, since it is an excavated sampler, sampling can be easily performed even with tight sand. Further, by equipping the tip with a water-blocking shoe, the drilling water and the sample can be completely blocked, and the sample can be completely prevented from flowing out by the drilling water.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an embodiment of a sampler according to the present invention (during excavation).

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is an overall configuration diagram of an embodiment of a sampler according to the present invention (when separated).

FIG. 4 is an enlarged view of a portion B in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Sampler 12 ... Outer tube 14 ... Inner tube 16 ... Core tube 18 ... Bit 20 ... Coupling head 22 ... Boring rod 24 ... Swivel 28 ... Piston 34 ... Intermediate tube 38 ... Flexible tube 44 ... Waterproof shoe 64 ... Check valve 82 ... Check valve fixing piston

Claims (1)

[Claims] 1. An outer tube having a bit at a lower end portion, an inner tube rotatably housed inside the outer tube, a core tube housed inside the inner tube, and an inside of the inner tube. An intermediate tube housed in the core tube and detachably joined to the core tube; a water-impervious shoe provided at a distal end portion of the inner tube or the intermediate tube and protruding from a distal end of the bit; A flexible tube that is attached to the outer periphery of the joint portion of the intermediate tube in a twisted state in advance and connects the core tube and the intermediate tube, and moves in a direction that relatively separates the core tube and the intermediate tube. Moving means for moving the core tube and the intermediate tube relatively away from each other, so that the diameter of the pre-twisted flexible tube is reduced and A sampler characterized by closing a lower end of a core tube.