Sampling device and sampling method

Abstract

To propose a sampling device and sampling method that can collect a sample while minimizing the load applied to the sample.SOLUTION: A sampling device 1 comprises: a core tube 2 for taking a sample into its interior; a connection rod 3 connected to a proximal end of the core tube 2; and a drilling device 4 for applying turning force and push-in force to the connection rod 3. An through-hole 26 is formed in the proximal end face of the core tube 2, and a sample can be extruded from the core tube 2 by means of an extrusion rod 5 inserted from the through-hole 26.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a sampling device and a method for sampling. [Background technology]

[0002] When taking a boring core (sample) from the ground (including bedrock and improved ground), a core tube is attached to the tip of a boring rod, and the boring rod is rotated and pressed into the ground to take the boring core that is taken into the core tube. A bit is attached to the tip of the core tube, and the columnar boring core cut by the bit is taken into the core tube. When removing a drilled core from a core tube, if the drilled core is difficult to remove, it is common to strike the core tube to remove it, but the impact of striking the core tube may destroy the drilled core. Therefore, Patent Document 1 discloses a boring core extraction method in which a boring core is extracted using a core tube with a bit at its tip. The core tube in Patent Document 1 has a gel sheet on the inside and a friction reduction sheet on the inside of the gel sheet, thereby reducing the frictional force when extracting the boring core. However, even if the frictional force is reduced, some force must be applied to the boring core when removing the boring core from the core tube. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-197446 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a sample collection device and a sample collection method that make it possible to collect a sample while minimizing the load on the sample. [Means for solving the problem]

[0005] In order to solve such problems, the sample collection device of the present invention includes a core tube for taking in a sample, and a hole-making device for applying a rotational force and a pushing force to the core tube. A through hole is formed in the base end surface of the core tube, and the sample can be pushed out from the core tube by an extrusion rod inserted from the through hole. In addition, a sample collection method using this sample collection device includes a step of pushing the core tube into a sample collection target area to capture a sample into the core tube, a step of recovering the core tube, and a step of pushing the extrusion rod through the through hole of the core tube to extrude the sample from the core tube. According to the sample collection device and the sample collection method, the sample (boring core) is extracted from the core tube by pushing the sample out with the push rod, so there is no need to strike the core tube and no impact is applied to the sample. Therefore, the load on the sample when it is extracted from the core tube is minimized, and the sample is prevented from being damaged.

[0006] If a female thread is formed on the inner peripheral surface of the through hole and a male thread capable of being screwed into the female thread is formed on the extrusion rod, the sample can be gradually extruded by rotating the extrusion rod. Furthermore, if a plate material is pin-joined to the tip of the extrusion rod, or if an extrusion plate material that can be joined to the tip of the extrusion rod and has a shape larger than the cross-sectional shape of the extrusion rod is provided inside the core tube, the extrusion force of the extrusion rod can be prevented from being concentrated and acting on one point on the bottom surface of the sample, even if the extrusion rod is inclined with respect to the bottom surface of the sample. Furthermore, if a connecting rod having a male thread that can be screwed into the female thread is provided, the connecting rod can be connected to the core tube using the through hole, making it possible to collect samples from deep positions. Effect of the Invention

[0007] According to the sample collection device and sample collection method of the present invention, it is possible to collect a sample while minimizing the load on the sample. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view showing an overview of a sample collecting device according to a first embodiment. [Diagram 2] 1A is a side view of the core tube, FIG. 1B is a perspective view of the casing, FIG. 1C is a perspective view of the core bit, and FIG. 1D is a perspective view of the core head. [Diagram 3] FIG. 2 is a side perspective view showing a push rod. [Figure 4] 1 is a flowchart showing the steps of a sample collection method. [Diagram 5] FIG. 1 is a side view showing each step of a sample collection method, where (a) is a preparation step, (b) is a preparation step subsequent to (a), and (c) is a sample intake step. [Figure 6] FIG. 13 is an explanatory diagram of a method for breaking the joint between the tip of the sample and the ground. [Figure 7] FIG. 13 is a side view showing a sample extrusion process. [Figure 8] FIG. 11 is a side view showing an outline of a sample collecting device according to a second embodiment. [Figure 9] FIG. 6 is a cross-sectional view showing a core tube of a second embodiment. [Figure 10] FIG. [Figure 11] FIG. 2 is a cross-sectional view of a core head. [Figure 12] FIG. [Figure 13] 1A to 1C are cross-sectional views showing steps of a sample collection method, where (a) is a preparation step, (b) is a preparation step subsequent to (a), and (c) is a sample intake step. [Figure 14] FIG. 1 is a cross-sectional view showing a sample extrusion process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] First Embodiment In the first embodiment, a sampling method is described in which a borehole is drilled vertically into a sample collection object (concrete member, ground improvement body, ground, etc.) and a boring core (sample) having a diameter of 10 cm to 70 cm and a length of 30 cm to 2 m is collected. A sampling device 1 is used to collect the boring core. The sampling device 1 is shown in FIG. 1. As shown in FIG. 1, the sampling device 1 includes a core tube 2, a connecting rod 3, and a hole-drilling device 4.

[0010] The core tube 2 is shown in Fig. 2. As shown in Fig. 2(a), the core tube 2 includes a cylindrical casing 21, a core bit 22 attached to the tip of the casing 21, and a core head 23 attached to the base end of the casing 21. The core bit 22 bores a hole in the ground and takes a sample into the casing 21. The casing 21 is made of a steel pipe with a length of about 30 cm. A female thread 24 is formed on the inner surface of one end of the casing 21 (the end on the core bit 22 side in this embodiment), and a male thread 25 is formed on the outer surface of the other end (the end on the core head 23 side). When connecting multiple casings 21, the male threads 25 and female threads 24 are screwed together.

[0011] The core bit 22 is a cylindrical member with a cutting blade 22a formed (including fixed) at its tip (the end opposite the casing 21). The core bit 22 is made of a steel pipe with the same diameter as the steel pipe constituting the casing 21, and a male thread 25 that can be screwed into the female thread 24 of the casing 21 is formed at the base end (the end on the casing side) of the core bit 22. The core bit 22 is connected to the lower end of the casing 21 by screwing the male thread 25 at the base end into the female thread 24 of the casing 21 on the lower side. The core head 23 is made of a steel pipe, and a female thread 24 is formed on the inner surface of the tip end (the end on the casing 21 side), and the base end (the end opposite the casing 21) is shielded. The steel pipe constituting the core head 23 has the same diameter as the steel pipe constituting the casing 21. The core head 23 is connected to the upper end of the casing 21 (core tube 2) by screwing the female thread 24 into the male thread 25 of the casing 21. As shown in FIG. 2(d), a through hole 26 is formed in the center of the base end surface of the core head 23 (core tube 2). A connection rod 3 can be connected to the through hole 26. The through hole 26 has an inner diameter that allows the insertion of the extrusion rod 5 for extruding the sample taken into the casing 21. The through hole 26 of this embodiment is formed with a female thread.

[0012] The connecting rod 3 connects the core tube 2 and the hole drilling device 4. As shown in Fig. 1 and Fig. 2(a), the connecting rod 3 is connected to the base end of the core tube 2. The connecting rod 3 is made of a steel rod having an outer diameter larger than the inner diameter of the through hole 26. The tip of the connecting rod 3 is formed with a male thread that can be screwed into the female thread of the through hole 26. The connecting rod 3 is connected to the core tube 2 by screwing the tip into the through hole 26.

[0013] FIG. 3 shows the extrusion rod 5. The extrusion rod 5 is made of a steel rod, and is inserted into the core tube 2 through the through hole 26 to extrude the sample from the core tube 2. The extrusion rod 5 of this embodiment is formed with a male screw 51 that can be screwed into the female screw of the through hole 26. A plate material 52 is pin-joined to the tip of the extrusion rod 5. The plate material 52 has an outer shape that can pass through the through hole 26. Furthermore, an engagement part 53 that can be engaged with a tool such as a wrench is formed at the base end of the extrusion rod 5. The configuration of the engagement part 53 is not limited, and for example, the base end of the extrusion rod 5 may be processed into a polygonal cross section so that it can be gripped by a tool or the like, or a bolt may be screwed into the base end of the extrusion rod 5.

[0014] The hole-drilling device 4 applies a rotational force and a pushing force to the connecting rod 3. As shown in FIG. 1, the hole-drilling device 4 includes a drill 41 that applies a rotational force to the connecting rod 3, a guide portion 42 that supports the drill 41, and a base portion 43 that supports the guide portion 42. The guide portion 42 is vertically erected on the base portion 43. The base portion 43 is fixed to the surface of the object to be sampled via an anchor 45. The drill 41 moves up and down along the guide portion 42. In this embodiment, the drill 41 moves up and down by manually operating a handle 44, but the up and down movement of the drill 41 may be automatically controlled by using a power source such as a motor.

[0015] A sample collection method using the sample collection device 1 will be described below. Fig. 4 shows the steps of the sample collection method. In this embodiment, a borehole is drilled downward to collect a borehole core (sample). As shown in Fig. 4, the sample collection method includes a preparation step S1, a sample intake step S2, a core tube recovery step S3, and a sample extrusion step S4. Figs. 5 to 8 show the status of each step of the sample collection method.

[0016] In the preparation step S1, a hole drilling device 4 is installed at a predetermined position, and a core tube 2 is attached to the hole drilling device 4. First, as shown in FIG. 5(a), an anchor 45 is used to fix a base portion 43 at a predetermined position. Next, a drill 41 is attached to a guide portion 42. Then, a connecting rod 3 is attached to a base end portion of the core tube 2. Next, as shown in FIG. 5(b), a base end portion of the connecting rod 3 is attached to the hole drilling device 4.

[0017] In the sample taking-in step S2, as shown in FIG. 5(c), the core tube 2 is pushed into the sample collection area to take in the sample into the core tube 2. In the sample taking-in step S2, the drill 41 of the hole-making device 4 is driven to rotate the core tube 2 via the connection rod 3, and the handle 44 of the hole-making device 4 is operated (rotated) to move the drill 41 down along the guide part 42. In this way, the core tube 2 is pushed into the sample collection area while rotating around the axis of the connection rod 3. The core tube 2 drills the sample collection area with the core bit 22 to form a borehole, and takes in the sample (bored core) inside. The core tube 2 is pushed to a predetermined depth to take in a sample of a predetermined length.

[0018] In the core tube retrieval step S3, the core tube 2 with the sample taken in therein is retrieved. The core tube 2 is retrieved by operating the handle 44 (by rotating in the opposite direction to that in the sample taking-in step S2) to raise the drill 41, thereby taking the core tube 2 out of the borehole. If it is difficult to retrieve the borehole core (sample P) because the tip of the borehole core is fixed or bonded to the sample collection object, the top end of the core tube 2 is pushed laterally (horizontally) as shown in FIG. 6 to separate the tip of the borehole core from the sample collection object, and then the core tube 2 is retrieved. FIG. 6 is an explanatory diagram of a method for breaking the connection part between the tip of the sample P and the sample collection object.

[0019] In the sample extrusion step S4, the sample P is extruded from the collected core tube 2. FIG. 7 shows the sample extrusion step. As shown in FIG. 7, the sample P is extruded from the core tube 2 by pushing the extrusion rod 5 inserted into the through hole of the core tube 2 into the core tube 2. The extrusion rod 5 is pushed into the core tube 2 by rotating it using a tool engaged with the engagement portion 53. Since the plate material 52 is pin-joined to the tip of the extrusion rod 5, the tip of the extrusion rod 5 is in surface contact with the base end surface of the sample. Therefore, the extrusion force of the extrusion rod 5 acts on the sample P over a surface without being concentrated at one point, reducing the load on the sample P.

[0020] According to the sampling device 1 of this embodiment and the sampling method using the same, the sample P (boring core) is extracted from the core tube 2 by pushing out the sample P with the push rod 5, so there is no need to strike the core tube 2. Therefore, the load on the sample P when extracting it from the core tube 2 is minimized, and the sample P is prevented from being damaged, so that it can be extracted in a healthy state. Therefore, even if the sample P has viscosity, the sample can be easily extracted from the core tube 2. Moreover, the extrusion rod 5 is screwed into the female thread of the through hole 26 of the core head 23, and the load on the sample P is reduced by rotating the extrusion rod 5 to gradually extrude the sample P. In addition, since the plate material 52 is pin-joined to the tip of the extrusion rod 5, the extrusion force is not concentrated at one point on the sample P, and since the plate material 52 does not rotate together with the extrusion rod 5, it is possible to prevent a rotational force from being applied to the sample P at the contact portion between the tip of the extrusion rod 5 and the base end face of the sample P. Therefore, the load on the sample P is kept to a minimum.

[0021] Second Embodiment In the second embodiment, a sampling method will be described in which a borehole is drilled horizontally in an existing wall and a borecore (sample) is collected. A sampling device 10 is used to collect the borecore. Figure 8 shows the sampling device 10 of the second embodiment. As shown in FIG. 8, the sample collecting device 10 includes a core tube 20 and a hole drilling device 40.

[0022] 9 shows the core tube 20. The core tube 20 includes a cylindrical casing 21, a core bit 22 attached to the tip of the casing 21, a core head 23 attached to the base end of the casing 21, and an extrusion plate material 27 provided inside the casing 21. The core bit 22 bores a hole in the ground and takes a sample into the casing 21. The details of the casing 21 and the core bit 22 are similar to those described in the first embodiment, and therefore a detailed description thereof will be omitted.

[0023] The extruded plate material 27 is made of a plate material that can be joined to the tip of the extruder rod 50, is larger than the cross-sectional shape of the extruder rod 50, and has an outer diameter smaller than the inner diameter of the casing 21. FIG. 10 shows the extruded plate material 27. As shown in FIG. 10, a pair of recesses 27a, 27a are formed on the edge of the extruded plate material 27 so as to face each other across the center of the extruded plate material 27. The recesses 27a are formed by cutting off a part of the outer edge of the disk in an arc shape. The number of recesses 27a is not limited, and may be three or more. A through hole 27b is formed in the center of the extrusion plate material 27. The through hole 27b has an inner diameter that allows a center pin 47 (see FIG. 13) attached to the hole drilling device 40 to be inserted therethrough. The tip of an extrusion rod 50 can be fitted into the through hole 27b. In this embodiment, the tip of the extrusion rod 50 is reverse-threaded, and the tip of the extrusion rod 50 fits into the extrusion plate material 27 by rotating the extrusion rod 50 counterclockwise with the tip of the extrusion rod 50 in contact with the through hole 27b.

[0024] The core head 23 is made of a steel pipe. A female screw is formed on the inner surface of the lower end of the core head 23. The upper end of the core head 23 is shielded. The steel pipe constituting the core head 23 has the same diameter as the steel pipe constituting the casing 21. The core head 23 is connected to the end of the casing 21 (core tube 2) by screwing the female screw into the male screw of the casing 21. A through hole 26 is formed in the center of the base end surface of the core head 23 (core tube 20). The through hole 26 has an inner diameter that allows the connection of the drilling device 4 and allows the insertion of the extrusion rod 5 for extruding the sample taken into the casing 21. The through hole 26 of this embodiment is formed with a female screw. In addition, a locking portion 23a for locking the extrusion plate material 27 is formed inside the core head 23. FIG. 11 shows a cross-sectional view of the core head 23. 11(a) and (b), the locking portion 23a is a plate piece (strip-shaped protrusion) erected on the inner surface of the core head 23 at the base end (the end opposite to the end on the casing side) of the core head 23, and has an outer shape smaller than the recess 27a of the extruded plate material 27. The locking portion 23a can lock an edge portion of the extruded plate material 27 other than the recess 27a. The locking portion 23a is formed at a position separated from the bottom surface of the core head 23 by a gap equal to or larger than the thickness of the extruded plate material 27.

[0025] 12 shows the extrusion rod 50. The extrusion rod 50 is made of a steel rod, and is inserted into the core tube 20 from the through hole 26 to extrude the sample from the core tube 20. The tip of the extrusion rod 50 in this embodiment is formed with a reverse thread 54 that can fit into the through hole 27b of the extrusion plate material 27. In addition, the base end of the extrusion rod 50 is formed with an engagement part 53 that can be engaged with a tool such as a wrench.

[0026] The hole drilling device 40 applies a rotational force to the core tube 2. As shown in Fig. 8, the hole drilling device 40 of the second embodiment is a so-called hand drill. A rotating shaft 46 of the hole drilling device 40 can be attached to the through hole 26 of the core head 23. In addition, a center pin 47 can be attached to the rotating shaft 46.

[0027] The following describes a sample collection method using the sample collection device 10. The sample collection method includes a preparation step S1, a sample intake step S2, a core tube recovery step S3, and a sample extrusion step S4 (see FIG. 4). FIG. 13 shows the status of each step of the sample collection method.

[0028] In the preparation step S1, the core tube 20 is positioned. First, the core tube 20 is attached to the rotating shaft 46 of the hole drilling device 40. Next, the center pin 47 is inserted into the core tube 20 and attached to the rotating shaft 46 of the hole drilling device 40 (see FIG. 13(a)). At this time, the tip of the center pin 47 protrudes from the tip of the core tube 2 (core bit 22). Then, as shown in FIG. 13(a), the hole drilling device 40 is driven while pressing the center pin 47 against the wall surface to rotate the core tube 20 around the rotating shaft 46. A spring is inserted into the center pin 47, and the core tube 20 (core bit 22) is fixed to the wall surface until it comes into contact with the wall surface, as shown in FIG. 13(b). When the core bit 22 comes into contact with the wall surface, the wall surface is drilled by the core bit 22 to form a groove D. Once groove D of a predetermined depth (for example, 2 to 3 mm) is formed, core tube 20 is temporarily removed from the wall surface, and center pin 47 is removed.

[0029] In the sample taking-in step S2, as shown in Fig. 13(c), the core tube 20 is pushed into the wall to take in the sample into the core tube 20. In the sample taking-in step S2, the core tube 20 is rotated by driving the hole-drilling device 40 while the core bit 22 of the core tube 20 is pressed against the groove D formed in the wall. By pushing the core tube 20 rotating around the rotation axis 46 into the wall, the wall is drilled by the core bit 22 to form a borehole, and a sample (bored core) is taken inside. By pushing the core tube 20 to a predetermined depth, a sample of a predetermined length is collected.

[0030] In the core tube recovery step S3, the core tube 20 with the sample taken inside is pulled out from the borehole and recovered. If it is difficult to recover the borehole core because the tip of the borehole core is fixed or connected to the sample collection object, the upper end of the core tube 20 is pushed laterally (horizontally or vertically) to break the connection between the tip of the borehole core and the sample collection object, and then the core tube 20 is recovered.

[0031] In the sample extrusion step S4, the sample is extruded from the collected core tube 20. Figure 14 shows the sample extrusion step. First, the extrusion rod 50 is inserted into the through hole of the core head 23, and the tip of the extrusion rod 50 is rotated counterclockwise with the tip of the extrusion rod 50 in contact with the extrusion plate material 27, thereby fitting the tip of the extrusion rod 50 into the extrusion plate material 27. Furthermore, by rotating the extrusion rod 50, the position of the locking portion 23a of the core head 23 and the position of the recessed portion 27a of the extrusion plate material 27 are aligned (see Figure 11(b)). 14, the extrusion rod 50 is pushed further into the core tube 2, thereby pushing the sample P out of the core tube 20. When the extrusion rod 50 is pushed in, the extrusion plate material 27 moves inside the core tube 20, and the sample P is pushed out of the core tube 20.

[0032] According to the sample collection device 10 of this embodiment and the sample collection method utilizing the same, an extrusion force is applied to the sample P via an extrusion plate material 27 having a relatively large area (an area close to the cross-sectional area of ​​the sample P), so that the load on the sample P when the sample is extruded is small, and damage to the sample P can be suppressed. Since the core tube 20 is positioned using the center pin 47, the core tube 20 can be prevented from shaking without fixing the hole drilling device 40. According to the sample collecting device 10 of the second embodiment and the sample collecting method using the same, it is possible to obtain the same effects as those of the first embodiment.

[0033] Although an embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and each component can be appropriately modified without departing from the spirit of the present invention. For example, the subject of sampling is not limited. Furthermore, the configuration of the hole drilling devices 4, 40 is not limited. The through hole 26 of the core tube does not necessarily have to be female-threaded. Similarly, the connecting rod 3 and the pusher rod 5 do not necessarily have to be externally threaded. Moreover, instead of the center pin 47, a center drill may be used. In each of the above embodiments, a hole-drilling device 4, 40 or a connecting rod 3 is attached to the through hole 26 of the core tube 2, 20, and an extrusion rod 5, 50 is inserted into the through hole 26. However, a through hole 26 dedicated to the extrusion rod may be formed in the core tube 2, separate from the drilling device 4, 40 or the connecting rod 3 and the mounting portion. Additionally, the push rods 5, 50 may be provided with handles at their proximal ends. The length of the casing 21 and the shape of the sample P (boring core) to be collected are not limited to those shown in the figure. [Explanation of symbols]

[0034] 1,10 Sampling device 2,20 Core tube 21 Casing 22 Core bit 23 Core Head 26 Through hole 27 Extrusion Plates 3 Connecting Rod 4,40 Drilling equipment 5,50 Extrusion Rod P sample

Claims

1. A core tube for incorporating a sample therein; A sample collection device comprising: a drilling device that applies a rotational force and a pushing force to the core tube, A through hole is formed in the base end surface of the core tube, A sample collecting device, characterized in that the sample can be pushed out from the core tube by an extrusion rod inserted through the through hole.

2. A female screw is formed in the through hole, 2. The sample collecting device according to claim 1, wherein the push rod is formed with a male thread that can be screwed into the female thread.

3. 2. The sample collecting device according to claim 1, wherein a plate member is provided at the tip of the push rod and joined with a pin.

4. 2. The sample collecting device according to claim 1, further comprising an extruded plate member inside said core tube, said extruded plate member being joinable to the tip of said extruder rod and having a cross-sectional shape larger than that of said extruder rod.

5. 3. The sample collection device of claim 2, further comprising a connecting rod having male threads that are matable with the female threads.

6. A sample collection method using the sample collection device according to any one of claims 1 to 5, forcing the core tube into the area to be sampled to capture a sample within the core tube; recovering the core tube; and pushing the extrusion rod through a through hole of the core tube to extrude the sample from the core tube.

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