JPH11303055A - Rotary type soil sampler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To permit sampling of soil specimens of different ground depth reliably, efficiently and at a low cost even though groundwater is present or a bore hole collapses easily. SOLUTION: A plurality of window portions 12 are formed at certain intervals in axial direction, and each window portion has a sampling pipe 10 provided with a blade 14 for scraping sample, a cone 16 installed to its lower end and a sampling head 18 provided at the upper end, and a partitioning member 22 forming an independent sample housing space by partitioning the inside of sampling pipe for each window portion. Partitioning member is communicated by the central coupling pipe 20 at the same intervals as window's and has a liquid-tight slidable construction compared to the sampling pipe, and the window portion is made freely openable. The window portion is opened only during sampling and rotating inside the hole thereby scraping the wall of a bore hole with each blade and the samples are housed in respective storing space.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary type soil sampler capable of collecting soil samples at different ground depths at a time, and more particularly, to a sampling having a blade and a window for shaving a soil sample. An inner sampler provided with a partition member slidable in a liquid-tight manner therewith and forming a different sample accommodating space therein is inserted into the tube, and the position of the inner sampler in the axial direction is adjusted, whereby a window is formed by the partition member. The present invention relates to a rotary type soil sampler that can be freely opened and closed. Although this soil sampler is not particularly limited, it is effective when groundwater is present.For example, in combination with the cone penetration test, the soil sampler is used for the cone penetration test using the hole formed by the cone penetration test. This is a technique suitable for easily and accurately examining the soil distribution by sampling a soil sample at intervals corresponding to the specified penetration amount.

[0002]

2. Description of the Related Art A cone penetration test is performed as a ground survey method for determining relative values of soil hardness and tightness at an original position. This is a penetration test method in which a penetrating rod with a cone attached to the tip is driven into the ground by free-falling a hammer with a specified weight from a specified height, and a fixed depth (specified penetration amount) The number of hits from a certain drop height required for driving is used as the measured value of the ground resistance. By plotting a penetration test value (number of hits: Nd value) with respect to the ground depth, a penetration curve can be obtained, and a soil distribution (distribution of soil hardness and tightness) can be obtained from the penetration curve.

[0003] One type of penetration test is a test method called a standard penetration test. This is sounding performed using a borehole, and a soil sample can be collected at the same time using a standard penetration test sampler. The standard penetration tester consists of a shoe, a split barrel that can be split, and a connector head.
The sample can be observed because it can be relatively easily decomposed. Specifically, the test is performed as follows. Drill a borehole to the required depth for a standard penetration test. Do not disturb the soil below the hole bottom and remove the slime at the bottom of the hole. Connect the sampler to the rod and gently lower it to the bottom of the hole. Attach the sampling head and guide rod to the upper part of the rod. Preliminary, final, and final strikes are performed by hammering. Record the number of hits required for the specified amount of penetration in the final hit. The sampler is lifted to the surface of the ground, the sampler is disassembled, and a sample is taken out and observed. By repeating such operations, the soil distribution can be obtained.

[0004] Therefore, although a soil sample can be collected in the standard penetration test, excavation of a boring hole and collection of a soil sample at each depth must be performed, and the operation is complicated and time-consuming. In addition, since the penetrating tip has a tube structure, it is necessary to secure sufficient rigidity, and the diameter of the sampler increases (the outer diameter of the sampler is 51 mm).

On the other hand, in a cone penetration test in which the penetration tip is a cone type, the outer diameter can be reduced, and the number of hits required for a predetermined penetration amount at each depth can be continuously obtained, so that it is simple and quick. This has the advantage that the test can be performed efficiently, but the soil sample cannot be collected. If the soil is different (whether the part is clayey, sandy, or gravel, etc.), the evaluation of the strength of the soil and the like differs even with the same number of impacts. Therefore, it is absolutely necessary to actually collect a soil sample and visually observe it in combination with sampling by boring, but sampling by boring is very expensive. Therefore, for example, in soil surveys over long distances when constructing roads and railroads, or in soil surveys over large areas such as buildings, sampling by boring at appropriate intervals to collect soil samples and complement them A method has been adopted in which a cone penetration test is performed in such a manner that soil properties are estimated from the penetration test values, and a soil distribution over the entire ground is obtained.

[0006]

In order to reduce costs, it is advantageous to minimize the number of boring samples and increase the number of cone penetration tests. The soil distribution based on the number of hits) is only an estimate, and there is no guarantee that such soil is actually distributed. In order to obtain an accurate soil distribution, soil samples must be sampled by drilling as densely as possible, which is costly and time consuming.

[0007] Therefore, there is a demand for the development of a simple technique capable of obtaining an accurate soil distribution at a low cost, particularly even on a ground over a wide range and a long distance. As a solution to such a technical problem, the present inventor has previously established a rotary type of structure in which a large number of sampling units are cascade-connected, a cone is attached to the distal end, and a penetrating rod is connected to the proximal end. A soil sampler was proposed (see Japanese Patent Application No. 9-322088). Here, each sampling unit includes a sampling pipe having an interior serving as a storage space for a soil sample and having a window formed on a side wall, a blade for cutting a soil sample attached to the window of the sampling pipe, and an end of the sampling pipe. The structure has a coupling for closing the portion and connecting to an adjacent sampling unit.
Then, by inserting the blade into a hole formed in the ground and rotating the blade, each blade scrapes the hole wall and accommodates the hole in each sampling unit.

[0008] This soil sampler is simple in structure, but is capable of shaving the soil sample at each depth at a time only by making a single rotation in a hole formed in the ground, and quickly at predetermined intervals. It is an excellent device that can easily obtain soil samples at different depths. However, when groundwater is present, when the soil sampler is inserted into the hole, the surrounding earth and sand flows into the sampling unit together with the groundwater, so that there has been a problem that it is not possible to reliably collect only the soil sample at a predetermined depth. . The same applies to the ground where the hole wall is easily collapsed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a simple soil sampler which can collect soil samples at different ground depths at one time and can reliably determine the soil properties by visual observation. Another object of the present invention is to ensure that only soil samples at a predetermined depth can be collected efficiently and inexpensively, even on ground where groundwater is present or where the pore walls are likely to collapse. The purpose of the present invention is to provide an improved soil sampler.

[0010]

According to the present invention, there is provided a sampling pipe having a plurality of windows formed at intervals in an axial direction and having a blade for cutting a sample in each of the windows, and a lower end of the sampling pipe. A soil sampler comprising a mounted cone and a sampling head provided at an upper end, and a partition member that partitions the inside of the sampling tube for each window to form an independent sample accommodating space. Here, in the present invention, an inner sampler is inserted into the sampling pipe, and a plurality of partition members are connected to each other at the same interval as the window by a connecting pipe, and each of the partition members is connected to the sampling pipe by a liquid. The partitioning member has a structure that can be slid densely, and the inner sampler is moved in the axial direction so that the window corresponding to the partition member can be freely opened and closed.

This soil sampler is inserted into a hole formed in the ground. At this time, the position of the inner sampler in the axial direction is adjusted so that all the windows are closed by the respective partition members, thereby preventing earth and sand from entering the windows during the insertion process. When sampling is started at a predetermined depth, the axial position of the inner sampler is adjusted, and the position of each partition member is shifted to open each window. Then, by rotating the sampling tube, each blade cuts the hole wall and accommodates it in each sample accommodating space. After sampling, adjust the axial position of the inner sampler again so that all windows are closed by the partition members, prevent earth and sand from entering the windows during the extraction process, and Raise the whole. In this way, a soil sample at each depth can be collected.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS For example, in an inner sampler, a plurality of partition members having a central through hole and a central connecting pipe are alternately connected in an axial direction so as to maintain a communication state, and an inner surface of the sampling pipe is provided. The sample storage tubes are arranged so as to be close to each other with a slight gap therebetween, and the lower end of the sample storage tubes is fixed to each partition member, and O.D.
The structure is such that a ring is attached to the inner surface of the sampling tube so that it can slide in a liquid-tight manner. By moving the inner sampler in the axial direction, the partition member can open and close the corresponding window. The window is opened only at the time of sampling, and the sample is received in the sample storage tube.

In a preferred embodiment, an inner sampler head is connected to the upper end of the uppermost central connecting pipe, and the inner sampler head is provided so as to be located inside the sampling head. In that case, at the time of non-sampling, a lifting prevention screw of the inner sampler is screwed onto the upper end of the sampling head, and the inner sampler head is pushed down by the tip of the lifting prevention screw, so that the partition member closes the window. Be fixed. Also, at the time of sampling, an inner sampler lifting tool having a screw portion with a smaller diameter than the lifting prevention screw is installed on the upper portion of the sampling head, and the screw portion is screwed on the upper portion of the inner sampler head to pull up the inner sampler. Each partition member can be held at a position separated from each window.

The window opening on the side wall of the sampling tube is formed, for example, in a substantially rectangular shape, and the blade for cutting off the sample is welded at one side edge and upper and lower edges of the window. Attach so that a part of the part is covered and the cutting edge projects slightly outward.

Although the sampling pipe may be long, it is preferable that the sampling pipe be unitized and connected and extended by an arbitrary number between the cone at the lower end and the sampling head at the upper end by a connection coupling. Then, it is possible to easily cope with an arbitrary ground depth. In order to extend the inner sampler, it is possible to cope only by sequentially adding the required number of center connection pipes and partition members.

[0016]

1 and 2 are explanatory views showing one embodiment of a rotary soil sampler according to the present invention. FIG. 1 shows a state at the time of non-sampling (a state in which a window is closed). 2 shows a state at the time of sampling (a state in which the window is opened).

This soil sample sampler has a sampling tube 10 on the outside, and a large number of windows 12 are formed in the sampling tube 10 at predetermined intervals in the axial direction (for example, five at intervals of 20 cm). Each window 12 is provided with a blade 14 for shaving a soil sample. Sampling tube 10
A cone 16 is attached to the lower end of the sample, and a sampling head 18 is attached to the upper end. The window 12 formed in the sampling tube 10 has a substantially rectangular shape when viewed from the side, and the blade 14 for shaving the sample is welded to one side edge of the window 12 and the upper and lower edges. As can be seen from the cross-sectional view shown in FIG. 3 (cross section taken along the line AA in FIG. 2), the window 12 is attached so as to cover a part of the window 12 and to protrude slightly outside.

An inner sampler is inserted into the sampling tube 10. In this inner sampler, a plurality of partition members 22 are continuously provided at the same interval as the window portion 12 by the central connecting pipe 20,
Each partition member 22 is structured to be slidable in a liquid-tight manner with respect to the sampling tube 10. Sampling tube 10
The area partitioned by the partitioning member 22 inside becomes a sample accommodating space. Here, the plurality of partition members 22 having the center through-holes 24 and the center connection pipe 20 are alternately connected in the axial direction so as to be in a communicating state. That is, it is completely connected from the central through hole of the lowermost partition member to the uppermost central connecting pipe, and air can flow between the lower cavity 26 and the upper cavity 28.

Also, the sample storage tube 3 is positioned close to the inner surface of the sampling tube 10 with a slight gap.
0 is placed. The sample storage tube 30 is fixed to each partition member 22 at the lower end. The length of the sample storage tube 30 is
The distance between the upper end and the lower surface of the upper partition member is set so as to substantially coincide with the height of the blade 14 for shaving the soil sample (in other words, the height of the window 12). Further, circumferential grooves are formed in the outer peripheral surface of each partition member 22 at two locations (the lowermost partition member may be located at one location) and at intervals equal to or greater than the height of the window portion 12 in the axial direction. By fitting the O-rings 32 in the respective circumferential grooves, a structure is slidable in the axial direction in a liquid-tight manner with respect to the inner surface of the sampling tube 10.

An inner sampler head 34 is connected to the upper end of the uppermost central connecting pipe, and is located inside the sampling head 18. The inner sampler head 34 has a lower large-diameter portion and an upper small-diameter portion, and the uppermost central connecting pipe is screwed to the lower large-diameter portion, so that the upper cavity 28 communicates with the outside. Is provided with an air flow hole 36. In addition, the stepped portion 34a between the small diameter portion and the large diameter portion of the inner sampler head 34 hits the stepped portion 18a on the inner surface of the sampling head 18, so that the inner sampler is positioned when ascending.

At the time of non-sampling, as shown in FIG.
A lifting prevention screw 40 of the inner sampler is screwed to the upper end of the sampling head 18. The lifting prevention screw 40
The lower end of the inner sampler head 34 is pushed down at the lower end so that each partition member 22 can be fixed at a position where each window portion 12 is closed. On the other hand, at the time of sampling, as shown in FIG. 2, instead of the lifting prevention screw, an eyebolt structure having a screw portion 42 having a smaller diameter than the above screw is used, and an inner sampler pulling tool in which a locking nut 44 is screwed. 46 is set on the upper part of the sampling head 18 and its screw 4
2 is screwed onto the upper portion of the inner sampler head 34.

The procedure for assembling the apparatus is as follows. The sampling head 18 is attached to the upper part of the sampling tube 10. It is desirable to fix by welding or the like. In the inner sampler, a sample accommodating tube 30 is attached to the partition member 22, and the required number of the center connecting tubes 20 are alternately connected thereto.
Assemble by attaching. The sampler is inserted into the sampling tube 10 and a cone 16 is mounted on the lower part. Then, as shown in FIG. 1, a lifting prevention screw 40 of the inner sampler is screwed to the upper end of the sampling head 18. When the inner sampler head 34 is pushed down by the lower end of the lifting prevention screw 40, the tip of the lowermost partition member hits the cone 16 and stops, whereby the partition member 22 is fixed at a position where the window portion 12 is closed.

Hereinafter, a method of using the present apparatus will be described. The soil sampler assembled as described above is driven into the cone penetration test hole to a predetermined depth. In addition,
The outer diameter of the sampling tube 10 is approximately equal to or slightly larger than the diameter of the hole to be driven. Usually, in order to protect the head of the lifting prevention screw 40, a cylindrical knocking head (not shown) is put on the upper part of the sampling head 18, and the sampling head 18 is hit with a hammering force. Of course, depending on the state of use, it is also possible to apply pressure instead of the hammering force of the hammer. In any case, when this soil sampler is driven to a predetermined depth in the hole, as shown in FIG.
Since each of the windows 12 is kept closed by the partition member 22, even if groundwater exists in the hole,
At the same time, there is no possibility that earth and sand will enter the sampling pipe.

After the soil sampler is driven to a predetermined depth in the existing hole, the lifting prevention screw is removed, and the inner sampler lifting tool 46 is set on the upper part of the sampling head 18. That is, the lower portion of the screw portion 42 is screwed to the inner sampler head 34, and the inner sampler is pulled up using a portion of the eyebolt using a winch or the like. The lifting is performed until the step 34a of the inner sampler head 34 hits the step 18a on the inner surface of the sampling head 18,
The locking nut 44 is lowered, and the state is maintained as shown in FIG. Of course, the inner sampler can be pulled up by rotating the locking nut 44. This state is a state in which the partition member 22 has moved in the axial direction and each window 12 has been opened. When pulling up the inner sampler, the air circulation hole 36, the upper cavity 28,
0, since air flows into the lower cavity 26 through each center through hole 24, the inner sampler can be lifted with a force that overcomes the weight of the inner sampler and the frictional force of the O-ring 32.

Next, the sampling head 18 is rotated substantially once. Then, the sampling tube 10 is also rotated, and the hole wall of each depth is cut off by each blade 14, and the soil sample enters the sampling tube 10 through the window 12 and is stored in the sample storage tube 30.

The inner sampler lifting tool 46 is removed, and the lifting prevention screw 40 is attached, and each window 12 is closed by the partition member 22. In that state, pull out the entire sampler. When the cone 16 is removed from the sampling tube 10, the inner sampler containing the soil sample can be taken out.

In the above description, the description is omitted for the sake of simplicity. However, as shown in FIG. 4, a plurality of sampling tubes 10 are cylindrical and have connection screw portions at both ends. The structure is extended to a predetermined length by the coupling 50. And a cone on their lower end,
A sampling head is provided at the upper end. The inner sampler can correspond to an extended sampling pipe by connecting a required number of center connection pipes and partition members.

Although the preferred embodiment of the present invention has been described in detail, the present invention is not limited to such a structure. Having a sample collection tube makes it easier to handle the collected soil sample, but even with the partition member only,
It is possible to take samples that are sectioned at each depth.
Of course, a partition member having a structure integrated with the sampling tube may be used. In addition, although the air flow passage is formed by the center connecting pipe and the center through hole, other means may be used, and depending on the design, a special air flow passage may not be provided. In order to carry out the present invention, not only the cone penetration test hole but also any existing hole can be used.

[0029]

As described above, according to the present invention, since the window provided with the blade for shaving the soil sample can be freely opened and closed by the partition member, the window is closed during non-sampling. By opening the window only at the time of sampling, it is possible to reliably collect only a soil sample at a predetermined depth, for example, even in the ground where groundwater is present, or in the ground where the hole wall is likely to collapse. It becomes possible. Further, since the apparatus of the present invention is a rotary type soil sampler provided with multi-stage windows having blades, it is possible to collect soil samples at different ground depths at once, which is extremely efficient and reduces costs. it can. In particular, it is extremely useful as a simple soil sampler that can be used to reliably determine soil properties by visual observation in combination with a standard penetration test.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a closed state of a window of an embodiment of a soil sampler according to the present invention.

FIG. 2 is an explanatory view showing the window open state.

FIG. 3 is a cross-sectional view at the position of a window.

FIG. 4 is an explanatory diagram of connection between sampling tubes.

DESCRIPTION OF SYMBOLS 10 Sampling tube 12 Window 14 Sample shaving blade 16 Cone 18 Sampling head 20 Center connecting tube 22 Partition member 24 Center through hole 30 Sample storage tube 32 O-ring 34 Inner sampler head 40 Floating prevention screw 46 Inside Sampler lifting tool

Claims (5)

[Claims] 1. A sampling tube in which a plurality of windows are formed at intervals in an axial direction and each window is provided with a blade for cutting off a sample, and a cone mounted on a lower end of the sampling tube and provided on an upper end. A sampling head and a partition member for partitioning the inside of the sampling tube for each window to form an independent sample accommodating space, and each blade is inserted into a hole formed in the ground and rotated, so that each blade is a hole wall. In the soil sampler sampler which is cut into each sample storage space, an inner sampler is inserted into the sampling pipe, and a plurality of partition members are continuously provided at the same interval as the window by a connecting pipe. , Each partition member has a structure capable of sliding in a liquid-tight manner with respect to the sampling tube, and by moving the inner sampler in the axial direction, the partition member opens and closes a corresponding window. An ability, rotary soil sample sampler by opening the sampling only when the window portion, characterized in that a sample scraped off by the blade and adapted to receive the specimen housing space. 2. A sampling tube in which a plurality of windows are formed at intervals in the axial direction and each window is provided with a blade for cutting off a sample, and a cone mounted on the lower end of the sampling tube and provided on the upper end. A sampling head and a partition member that separates the inside of the sampling tube for each window to form an independent sample accommodating space, and each blade is inserted into a hole formed in the ground and rotated, so that each blade has a hole wall. In the soil sampler, the inner sampler is inserted into the sampling tube, and the inner sampler communicates with a plurality of partition members having a center through hole and a center connection tube. Arranged alternately in the axial direction so as to maintain the state, arranged the sample storage tube so as to be close to the inner surface of the sampling tube with a slight gap,
The lower end of the sample storage tube is fixed to a corresponding partition member, and an O-ring is attached to the outer peripheral surface of each partition member to form a structure capable of sliding in a liquid-tight manner with respect to the inner surface of the sampling tube. By moving in the axial direction, the partition member can open and close the corresponding window, the window is opened only at the time of sampling, and the sample shaved by each blade is received in the sample storage tube. A rotary type soil sampler characterized by the following. 3. An inner sampler head is connected to the upper end of the uppermost central connecting pipe, and the inner sampler head is located inside the sampling head. When not sampling, the inner sampler head is connected to the upper end of the sampling head. The lifting prevention screw is screwed in, and the inner sampler head is pushed down by the tip of the lifting prevention screw so that the partition member is fixed at the position where the window is closed. During sampling, the diameter is smaller than that of the lifting prevention screw. At the position where each partition member comes off from each window by installing the inner sampler lifting tool having the screw part on the upper part of the sampling head, screwing the screw part on the upper part of the inner sampler head, and pulling up the inner sampler The rotary soil sampler according to claim 2, wherein the sample can be held. 4. A window formed on a side wall of the sampling tube has a substantially rectangular shape, and a blade for cutting a sample is welded to one side edge of the window and upper and lower edges. The rotary soil sampler according to any one of claims 1 to 3, wherein the rotary soil sampler is attached so as to cover a part of the window and to protrude slightly from the cutting edge. 5. The rotating tube according to claim 1, wherein the sampling tube is unitized and can be connected and extended by an arbitrary number between the lower end cone and the upper end sampling head by a connection coupling. Type soil sampler.