JP7274169B2 - Soil sampling device for soil improvement - Google Patents

Description

TECHNICAL FIELD The present invention relates to an apparatus for collecting soil samples for confirming the effects of ground improvement.

In soil improvement work that improves bearing capacity by injecting chemicals with hardening action into soft ground, reclaimed land, or other ground with weak bearing capacity, samples are taken from the improved part to confirm the effect. to be done. Soil samples are generally obtained by selecting a sampling position within the improved area, drilling a core drill to a predetermined depth, and collecting a predetermined sample at the tip.

As an example, in Patent Document 1, a prop is provided in front of a self-propelled cart, a core cutter and a soil sampler that move up and down and turn along the prop are attached, and after the soil is drilled by the core cutter, the soil sampler It is described that the work is automated so that the sample is collected by

Further, Patent Document 2 describes a handle-hammer type soil sampler for the purpose of labor-saving work of penetrating a soil sampling tube into the soil to a predetermined depth and pulling it out to collect a soil sample.

Furthermore, in Patent Document 3, a carriage with wheels towed by a tractor is attached with a disk-shaped rotating blade that cuts into the soil, and a plurality of soil samplers are provided at different positions on the side surface of the disk, It is described that a plurality of samples with different depths are collected to save labor in sample collection.

JP 2011-196140 A JP-A-2005-36405 JP-A-11-83696

In the methods or devices described in Patent Document 1 and Patent Document 2, each time soil is sampled, a hole is drilled at the sampling location or a soil sampling pipe is penetrated into the soil. , the number of vertical holes must be excavated or the excavation pipe must be penetrated into the soil, which is extremely troublesome.

In addition, the techniques described in Patent Document 1 and Patent Document 3 require a self-propelled trolley or tractor to run around on soft ground to collect samples. cannot be adopted in some cases. Furthermore, in the technique described in Patent Document 3, since samples can only be collected to a depth corresponding to the radius of the rotating blade, it cannot be adopted as a practical problem in ground improvement work at a depth exceeding 5 m, for example.

SUMMARY OF THE INVENTION An object of the present invention is to realize an epoch-making sampling device that can efficiently collect samples without digging a vertical hole at the sampling position each time a sample is collected. .

The device of the present invention includes a support pipe that serves as a guide inserted into a boring hole used for ground improvement work, a guide block provided at the tip of the support pipe, and a guide block that is inserted into the support pipe. and a sampling pipe protruded from the guide block and penetrated into the soil improvement portion in which the chemical solution is injected and is in a fluid state, and the guide block intersects with the boring hole. and a smooth guide curved surface connecting the opening and the portion to which the support pipe is connected. The collection tube is a flexible tube that is provided on the distal end side, bends along the guide curved surface as it advances along the guide curved surface, and enters the soil of the ground improvement portion from the opening. a section, a sample storage section for storing the soil of the ground improvement portion, and an openable and closable sampling port provided to allow the soil to enter the sample storage section , and the sampling tube includes an outer tube and and an inner tube that is inserted into the outer tube and protrudes relatively from the distal end of the outer tube, the flexible tube portion being provided in the outer tube, and the inner tube being the flexible tube. A flexible sampling tube that bends together with the flexible tube portion is provided at the distal end portion, and the sample storage section and the sampling port are provided in the sampling tube, and the sampling port is formed by connecting the sampling tube to the outer tube. The soil sampling device of the ground improvement part is characterized in that it is opened by protruding from and closed by the outer tube by pulling the sampling tube back into the outer tube.

In the device of the present invention, the flexible tube portion may be composed of a coil spring that generates propulsion force by rotating around a central axis in the soil of the ground improvement portion.

According to the present invention, the device of the present invention is inserted into the soil using a boring hole used for ground improvement work, that is, chemical injection work, and in a state that has not yet solidified, the radius centered on the boring hole Since samples can be collected from any position in any direction, there is no need to dig vertical holes corresponding to the number of samples, so soil samples can be collected very efficiently, and the work period for soil improvement work can be shortened. .

BRIEF DESCRIPTION OF THE DRAWINGS It is a conceptual diagram explaining the soil sampling method in the ground improvement of this invention Example. FIG. 3 is a conceptual diagram showing the initial state of the soil sampling work of the embodiment of the present invention; FIG. 4 is a conceptual diagram showing the second stage of the soil sampling operation of the embodiment of the present invention; FIG. 4 is a conceptual diagram showing the third stage of the soil sampling operation of the embodiment of the present invention; FIG. 4 is a conceptual diagram showing the fourth stage of the soil sampling operation of the embodiment of the present invention; FIG. 4 is a perspective view showing a guide block in an embodiment of the present invention; FIG. 4 is a perspective view showing tip portions of an outer tube and an inner tube in an embodiment of the present invention; FIG. 11 is a partial perspective view showing another example of the inner tube;

Preferred embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a conceptual diagram explaining the whole ground improvement work of the present invention. Of the ground G, the ground improvement portion to be improved is indicated by symbol R, and a cylindrical portion having a diameter B and a depth D centered on a central borehole (for example, a vertical hole) H is to be improved. Soil improvement is performed by a so-called jet construction method in which a nozzle is inserted into the vertical hole H and a chemical solution is sprayed horizontally into the soil while rotating the nozzle.

The inner diameter A of the vertical hole H for spraying the chemical liquid is, for example, about 40 mm to 200 mm depending on the diameter of the hose or pipe used for supplying the chemical liquid. Therefore, it is necessary to make the horizontal length of the guide block 4 somewhat smaller than its inner diameter A so that it can be inserted into the vertical hole H.

The sampling device is a triple tube consisting of a guide tube 1, an outer tube 2, and an inner tube 3. A guide block 4 is attached to the lower end of the guide tube 1, and the guide block 4 is suspended to a predetermined depth. In this state, the guide tube 1 is held by the flange 12 . When the outer tube 2 and the inner tube 3 are pushed downward from above in this state, as will be described later, the tips of the tubes change their direction in a direction intersecting the vertical hole H, such as a horizontal direction, and the guide block 4 From the inside of the ground improvement part R, the sample is collected at the tip of the inner pipe 3. The method of the present invention is a method of collecting a soil sample in an unsolidified state. Therefore, the timing of suspending the guide block 4 in the vertical hole H is before the ground solidifies, such as immediately after the injection of the chemical solution is finished. be. Moreover, the hanging depth is the depth of the portion where solidification has not yet fully solidified and there is fluidity even though solidification has started. Therefore, the injection of the chemical solution into the soil and the sampling may be carried out continuously, and these works can be carried out on the same day or without delay, thereby shortening the construction period. The guide tube 1 corresponds to the support tube in the device of the present invention, and the outer tube 2 and the inner tube 3 correspond to the collection tube of the present invention.

2 to 5, the operation of the above apparatus will be described in chronological order.

In FIG. 2, the entire sample collecting device is about to be suspended in the vertical hole H by a hanging tool (not shown). are also housed above.

FIG. 3 shows the state in which the entire device is submerged to a predetermined depth. Since the depth to which the guide block 4 is submerged is determined by the position of the flange 12, the flange 12 is preferably positionally adjustable with respect to the guide tube 1.

Subsequently, as shown in FIG. 4, the outer tube 2 and the inner tube 3 are pushed downward from above. The pressing can be performed manually, or may be performed while rotating using a boring machine or the like.

It is preferable that the outer tube 2 has a bendable coil spring 22 at least about 1.5 m from the portion passing through the guide block 4 to the tip side. This is because by rotating around its own central axis (the central axis of the outer tube 2), a propulsive force can be generated in the soil. The front portion connected to the coil spring 22, that is, the upper portion in FIGS. It should be noted that this coil spring 22 corresponds to the flexible tube portion in the present invention.

The inner tube 3 also has a flexible tube 32 extending about 1.5 m from the portion passing through the guide block to the tip side, and the tip of the flexible tube 32 serves as a sample storage portion 33 . The distal end of the flexible tube 32 is sealed so that the sample storage section 33 has a closed structure. An opening (sampling port) O is provided at a predetermined distance behind the tip of the sample storage portion 33, and the front portion connected to the flexible tube 32, that is, the upper portion in FIGS. is configured as a straight pipe for inserting and removing the flexible tube 32 . The flexible tube 32 may be, for example, a resin tube. Further, the straight pipe of the inner pipe 3 may be a rod instead of a pipe because nothing is passed through the inner pipe.

Here, the guide block 4 will be described with reference to the perspective view of FIG. The guide block 4 according to the present invention has a hollow structure (box structure) as shown in FIG. 6, and a joint portion 41 is provided at a portion facing upward in use. The joint portion 41 is a portion for connecting the guide tube 1 and into which the outer tube 2 and the inner tube 3 are inserted, and serves as an opening for communicating the inside and outside of the guide block 4 . Therefore, this joint portion 41 corresponds to "the part where the support pipe is connected" in the present invention. On the other hand, an opening 42 opening in a substantially horizontal direction is formed in the lower portion which is substantially horizontal in use. It should be noted that the opening 42 does not necessarily have to be open in the horizontal direction, and in the present invention, it is sufficient if it is open in a direction that intersects the vertical hole H. The crossing angle with respect to the vertical hole H is generally more than 0 degrees and 90 degrees or less, for example, when the vertical downward direction is 0 degrees, and may exceed 90 degrees if necessary. When opening in the horizontal direction, the opening directions of the joint portion 41 and the opening portion 42 differ by approximately 90 degrees. A side surface of the guide block 4 parallel to a plane including the joint portion 41 and the opening portion 42 (upper surface in FIG. 6) serves as a lid 45 that can be opened.

A guide plate 43 is inserted between the inside of the joint portion 41 and the lower horizontal opening 42 to connect these portions to form a curved path with these portions at both ends. The surface of this guide plate 43 corresponds to the guide curved surface in the present invention. The outer tube 2 and the inner tube 3 are inserted through the guide tube 1 into the guide block 4 in advance, and the apparatus is suspended underground after setting the tip so that it stands by at the opening 42. . If a guide roller 44 is provided near the exit of the guide curved surface as shown in this figure, the outer tube 2 can be smoothly moved in and out. It is preferable that the upper and lower surfaces of the guide block 4 are sharpened as shown in the figure, since the resistance to pushing in and pulling up from the soil is reduced.

7 is a perspective view showing the distal end portions of the outer tube 2 and the inner tube 3. As shown in FIG. It can be advanced by pushing the coil spring 22 of the outer tube 2 into the soil. In the case of hard soil, a core drill 5 may be appropriately attached to the tip. The tip of the inner tube 3 is closed with a rubber plug or the like, and the tube behind it is cut open to form a sample storage section 33 . Further, when the outer tube 2 is rotated, the helical action of the coil spring 22 produces a screw action, which improves straightness in the soil.

To further explain the process of sampling, when the tip of the outer pipe 2 and the inner pipe 3 or the core drill 5 attached to the tip advances to a predetermined position in the state of FIG. Leaving the tube 3, only the outer tube 2 is slightly pulled up. By doing so, the inner tube 3 protrudes relatively from the outer tube 2 as shown in FIG. As a result, the sampling port O, which is the opening of the sample containing portion 33, opens. At this point, the inner tube 3 is vibrated or the like to cause the surrounding soil to enter the sample storage section 33, and when the outer tube 2 is protruded again at a suitable time, the sample storage section 33 is formed by the outer tube 2. The sampling port (sample containing portion 33) is closed by being covered, and the sample introduced into the sample containing portion 33 is secured. Therefore, in the present invention, "closing the sampling port" may be closing the soil, the vertical hole H, or the guide tube 1, even if the sampling port O itself does not have an opening/closing plate or an opening/closing lid. good. Then, if the outer tube 2 and the inner tube 3 are pulled up to the ground as they are, a soil sample can be collected. However, depending on the soil, the operation of protruding the outer tube 2 again may be omitted and the tube may be pulled up as it is. In addition, the sampling position of the soil sample can be known based on the length of the outer pipe 2 and the inner pipe 3 sent through the vertical hole H into the ground improvement portion.

Since the inner tube 3 mentioned in the above-described specific example is constructed so as to close the sampling port by being pulled relatively inside the outer tube 2, it is possible to reduce the number of movable parts. On the other hand, if the collected soil (sample) has low viscosity, the sample may flow out from the collection port O in the process of pulling up the inside of the guide tube 1, and the required amount may not be brought up to the ground side. When collecting such a low-viscosity sample, it is preferable to use an inner tube 3 configured as shown in FIG.

The inner tube 3 shown in FIG. 8 is an example in which a plurality of sample storage portions 33a, 33b, and 33c are provided inside. That is, the inner tube 3 made of a flexible material is closed at its distal end, and its interior is partitioned by partition walls P1 and P2 provided at predetermined intervals in the longitudinal direction. The interval and the number of these partitions may be appropriately determined according to need. Both sides of the first partition P1 on the front end side are sample storage portions 33a and 33b, and the rear side of the second partition P2 is a sample storage portion 33c. Sampling openings O1, O2, and O3 corresponding to the sample storage portions 33a, 33b, and 33c are provided at positions a predetermined distance behind the respective tip portions of the sample storage portions 33a, 33b, and 33c.

Therefore, in the inner tube 3 shown in FIG. 8, when the sampling openings O1, O2, and O3 are opened in the soil by relatively retracting the outer tube 2, low-viscosity soil (samples) are collected. It enters into the sample storage portions 33a, 33b, and 33c through the openings O1, O2, and O3. In this state, the sampling ports O1, O2, O3 are closed and the outer tube 2 and the inner tube 3 are pulled up. In the process, the inner tube 3 is suspended vertically. In this state, the sampling openings O1, O2, and O3 of the sample storage sections 33a, 33b, and 33c containing the samples are connected to the sample storage sections 33a. , 33b, and 33c, even if a low-viscosity sample flows out from the sampling ports O1, O2, and O3, the samples below the sampling ports O1, O2, and O3 do not flow out. , remain in the sample storage portions 33a, 33b, and 33c. That is, even soil (sample) with low viscosity and high fluidity can be collected in a required amount and pulled up to the ground side.

As is clear from the above description, the soil sample collection of the present invention involves injecting a chemical solution into the ground and leaving the soil in a sherbet state where the soil is not yet completely solidified, i.e., when the granular material and fluid such as liquid are mixed. It is preferable to carry out in a fluid state as a whole. According to the device of the present invention, the soil sample is collected by using the boring hole used for the soil improvement work instead of drilling a vertical hole from the ground toward the collecting position. Since the core drill and sampling tube are inserted in the direction intersecting the borehole from the bottom, there is no need to drill a vertical hole each time soil is sampled, making it possible to collect soil samples efficiently. As a result, it is possible to shorten the construction period and reduce the cost of ground improvement. In addition, in the present invention, the boring hole is not limited to a vertical hole, and may be curved or inclined.

DESCRIPTION OF SYMBOLS 1... Guide tube 2... Outer tube 3... Inner tube 4... Guide block 5... Core drill 12... Flange 22... Coil spring 32... Flexible tube 33, 33a, 33b, 33c... Sample storage Part 42... Opening 43... Guide plate G... Ground H... Longitudinal hole (boring hole) O1, O2, O3... Sampling port R... Ground improvement part.

Claims (2)

A support pipe that serves as a guide to be inserted into the borehole used for ground improvement work,
a guide block provided at the tip of the support tube;
a sampling tube that is inserted into the support tube and protrudes from the guide block so as to penetrate into the soil improvement portion in which the chemical solution is injected and is in a fluid state;
The guide block has an opening that opens in a direction intersecting the boring hole and communicates with a portion where the support pipe is connected, and a portion where the support pipe is connected and the opening. and a smooth guide curved surface that connects the
a flexible tube portion provided on the distal end side of the collecting tube, which advances along the guide curved surface, curves along the guide curved surface, and enters into the soil of the ground improvement portion from the opening; , a sample storage section for storing the soil of the ground improvement portion, and an openable and closable sampling port provided to allow the soil to enter the sample storage section,
The collection tube has an outer tube and an inner tube that is inserted into the outer tube and protrudes relatively from the distal end of the outer tube,
The flexible tube portion is provided on the outer tube, and the inner tube has a flexible collection tube at a distal end portion that bends together with the flexible tube portion,
The sample containing portion and the sampling port are provided in the sampling tube,
The sampling port is opened when the sampling tube protrudes from the outer tube, and is closed by the outer tube when the sampling tube is pulled back into the outer tube. Soil sampling device for ground improvement part.
The soil sampling device for the soil improvement part according to claim 1 ,
A soil sampling device for a soil improvement portion, wherein the flexible tube portion is composed of a coil spring that generates a propulsive force by rotating around a central axis in the soil of the soil improvement portion.

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