Rock core sampling system

Abstract

To provide a rock core sampling system capable of sampling rock cores without replacing a boring machine for sampling rock cores.SOLUTION: A rock core sampling system for sampling rock cores comprises a communicating space (hollow portion of hollow rod 50, opening 51a of tip bit 51) leading to a hole bottom 6 as a discharge outlet for rock powder drilled at the hole bottom 6, is installed on a drilling machine 5 that drills a hole forward from a tunnel face 4, and is equipped with a core sampler 2 that samples rock cores as the drilling machine 5 drills. The core sampler 2 is installed on the tip bit 51 of the drilling machine 5 by passing through the communicating space by pressure.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a rock core sampling system for sampling rock cores. [Background technology]

[0002] When excavating mountain tunnels in natural ground with complex geology, a survey is conducted ahead of the tunnel face to grasp the geological conditions ahead of the tunnel face as the excavation proceeds. For example, a drilling machine such as a jumbo drill or hydraulic hammer is used to survey the characteristics of the natural ground ahead of the tunnel face from machine data (drilling energy) during drilling (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-125296 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, when excavating mountain tunnels, it is necessary not only to perform drilling logging to grasp the hardness of the ground based on the drilling energy, but also to extract rock cores and conduct tests for uniaxial compressive strength and heavy metal content, if necessary. Because rock cores cannot be extracted with drilling machines such as jumbo drills and hydraulic hammers, it was necessary to switch to boring machines for extracting rock cores that can be fitted with core samplers to extract rock cores.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a rock core sampling system that solves the above-mentioned problems and can extract rock cores without having to replace the boring machine for rock core sampling. [Means for solving the problem]

[0006] The rock core sampling system of the present invention is a rock core sampling system for sampling rock cores, which is installed on a drilling machine having a communicating space leading to the bottom of the hole as an outlet for rock powder drilled at the bottom of the hole, and is equipped with a core sampler that collects the rock cores as the drilling machine drills, and the core sampler is installed on the tip bit of the drilling machine by passing through the communicating space by pressure. In addition, the core sampler of the rock core sampling system of the present invention comprises a sampling section installed on the tip bit of the drilling machine, and a fixing section fixed to the communicating space of the drilling machine and supporting the sampling section axially movably via a spring, and a slit may be formed at the end of the fixing section that abuts against the spring, opening toward the surface that abuts against the spring. In addition, the rock core sampling system of the present invention may be provided with a recovery tool that reaches the core sampler through the communicating space by pressure pumping and recovers the core sampler, and the recovery tool may be provided with a centralizer that abuts against the wall surface of the communicating space and supports the recovery tool at its axis. Effect of the Invention

[0007] According to the present invention, a core sampler can be installed during the process of drilling a hole with a drilling machine, and rock cores can be collected without having to drill again with a dedicated bit. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram showing a configuration of an embodiment of a rock core sampling system according to the present invention. [Diagram 2] FIG. 2 is a cross-sectional view showing the rock core sampling system installed on a drilling machine. [Diagram 3] FIG. 2 is an enlarged view of a main part of the rock core sampling system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Next, a mode for carrying out the present invention (hereinafter simply referred to as an "embodiment") will be specifically described with reference to the drawings. Referring to FIG. 1, the rock core sampling system 1 of this embodiment includes a core sampler 2 and a recovery tool 3.

[0010] The core sampler 2 has a sampling section 21 for sampling rock cores, and as shown in Fig. 2(a), is installed in a drilling machine 5 that drills a hole forward from the tunnel face 4. The sampling section 21 is a cylindrical body, and is installed in the drilling machine 5 so that one open end faces the hole bottom 6.

[0011] The drilling machine 5 on which the core sampler 2 is installed has a hollow rod 50 provided for the purpose of supplying air and water to the hole bottom 6 and discharging rock powder generated at the hole bottom 6. An opening 51a is formed in the center of the tip bit 51 of the drilling machine 5, which communicates with the hollow part of the hollow rod 50 and reaches the hole bottom 6. The opening 51a of the tip bit 51 and the hollow part of the hollow rod 50 function as a communication space from the tunnel face 4 to the hole bottom 6.

[0012] The drilling machine 5 uses, for example, a reverse circulation hammer system (hereinafter referred to as RC hammer). The RC hammer is a drilling device that uses a tip impact method. The RC hammer includes a hollow rod 50 with a tip bit 51 connected to the tip, and a boring machine (not shown) that holds the hollow rod 50 and applies rotational force and propulsive force. The RC hammer moves a piston 53 back and forth by supplying air from the outer periphery (the gap between the hollow rod 50 and the outer periphery rod 52) of a double tube rod consisting of a hollow rod 50 and an outer periphery rod 52, thereby generating an impact on the tip bit 51 at the tip. In the RC hammer, the rock powder drilled is discharged to the outside through a communication space (the opening 51a of the tip bit 51, the hollow part of the hollow rod 50).

[0013] As shown in FIG. 1, the core sampler 2 includes a cylindrical fixed part 23 that supports the sampling part 21 axially movably via a spring 22. The fixed part 23 includes a stopper 24. The stopper 24 is hinged and configured to be displaceable (movable) between a protruding state protruding from the peripheral surface of the fixed part 23 and a stored state housed within the fixed part 23 and retracted from the peripheral surface. The stopper 24 is biased in a direction protruding from the peripheral surface of the fixed part 23 by a spring (not shown), and engages with the connecting part of the hollow rod 50 as an engaged part, thereby fixing the fixed part 23 to the communication space. By fixing the fixed part 23, the sampling part 21 is installed at a predetermined position of the opening 51a of the tip bit 51. A spear 25 is provided on the rear end side of the fixed part 23, and by pulling the spear 25 rearward, the stopper 24 is displaced to a stored state retracted from the peripheral surface.

[0014] As shown in FIG. 3(a), a slit S is formed at the end of the fixing part 23 on the bottom side of the hole that abuts against the spring 22 and the circumferential surface. The spring 22 is provided to deal with the hardness and softness of the ground, and if rock powder accumulates between the collection part 21 and the fixing part 23, the function of the spring 22 is impaired. The slit S serves as an escape route for the rock powder, and can prevent the rock powder from accumulating in the spring 22 between the collection part 21 and the fixing part 23. FIG. 3(a) is an enlarged view and an arrow view of the region X shown in FIG. 1. FIG. 3(a) shows an example in which six slits S are formed, but the number and shape of the slits S may be appropriately set according to the quality and amount of the rock powder.

[0015] The core sampler 2 is installed by temporarily stopping the drilling operation of the drilling machine 5 when the drilling operation by the drilling machine 5 has progressed to the location where the core will be collected. The core sampler 2 is pumped through the hollow part of the hollow rod 50 by water pressure (or air pressure) and installed in the opening 51a of the tip bit 51 as shown in Figure 2(a).

[0016] When the core sampler 2 is pumped, the hollow portion of the hollow rod 50 cannot be sufficiently cleaned, and therefore rock powder adheres to the inner wall of the rod. As the core sampler 2 is pumped, the rock powder that adheres to the inner wall of the rod tends to accumulate on the spring 22 between the sampling portion 21 and the fixed portion 23. The slit S also serves as an escape route for this rock powder, preventing excess rock powder from accumulating on the spring 22, and the core sampler 2 is pumped smoothly to the specified position and installed.

[0017] After the core sampler 2 is installed, the drilling operation of the drilling machine 5 is started. The core sampler 2 is installed in the discharge path of the rock powder, so that a core (or a natural ground sample close to the rock core) is collected by the collection unit 21. Note that, since the discharge path of the air discharged together with the rock powder by the core sampler 2 is blocked, the air is discharged through the outside of the outer circumferential rod 52.

[0018] After a core of a predetermined length has been collected in the collection section 21, the drilling operation of the drilling machine 5 is stopped and the core sampler 2 is collected by the collection tool 3. The collection tool 3 is pumped by water pressure (or air pressure) through the hollow part of the hollow rod 50 to the position of the core sampler 2.

[0019] The recovery tool 3 has a cylindrical body 32 with a cable 31 connected to its rear end. The body 32 has a latch mechanism 33 at its tip that engages with the spear 25 of the core sampler 2. The body 32 has a centralizer 34 on the body.

[0020] When the retriever 3 is inserted into the hollow rod 50, the centralizer 34 abuts against the rod wall surface of the hollow rod 50 to support the retriever 3 (body portion 32) at the axis of the hollow rod 50, as shown in Figs. 2(b) and 3(b). Therefore, a space is secured between the outer periphery of the body portion 32 and the rod inner wall of the hollow rod 50. Fig. 3(b) is an enlarged view and an arrow view of region Y shown in Fig. 1. The centralizer 34 shown in Fig. 3(b) is an example in which the body portion 32 is cut from three directions to make it thinner, and a leaf spring plate is arranged in the remaining portion, but there is no particular limitation on the structure of the centralizer 34.

[0021] Rock powder newly generated during drilling with the core sampler 2 attached passes around the core sampler 2 and adheres to the inner wall of the hollow rod 50. The rock powder adhering to the inner wall of the rod becomes an obstacle when the recovery tool 3 is pumped. As a countermeasure, the recovery tool 3 is supported by the centralizer 34, and a space is secured between the outer periphery of the body 32 and the inner wall of the hollow rod 50. Therefore, the recovery tool 3 can be smoothly pumped to the position of the core sampler 2.

[0022] When the recovery tool 3 reaches the position of the core sampler 2, the spear 25 of the core sampler 2 engages with the latch mechanism 33. In this state, by pulling the cable 31, the stopper 24 enters the housed state, and the core sampler 2 connected to the recovery tool 3 is recovered.

[0023] As described above, this embodiment is a rock core sampling system 1 for sampling rock cores, which is installed on a drilling machine 5 having a communicating space (hollow portion of hollow rod 50, opening 51a of tip bit 51) leading to the bottom of the hole 6 as an outlet for rock powder drilled at the bottom of the hole 6, and is equipped with a core sampler 2 for sampling rock cores as the drilling machine 5 drills, and the core sampler 2 is installed on the tip bit 51 of the drilling machine 5 by passing through the communicating space by pressure. With this configuration, the core sampler 2 can be installed during the process of drilling holes with the drilling machine 5, and rock cores can be collected without having to drill holes again with a dedicated bit.

[0024] Furthermore, in this embodiment, the core sampler 2 comprises a collection section 21 installed on the tip bit 51 of the drilling machine 5, and a fixed section 23 that is fixed to the communicating space of the drilling machine 5 and supports the collection section 21 axially movably via a spring 22, and a slit S that opens toward the surface that abuts against the spring 22 is formed at the end of the fixed section 23 that abuts against the spring 22. With this configuration, the slits S can prevent excess rock powder from accumulating in the spring 22, so that the core sampler 2 can be smoothly pumped to the designated position and installed.

[0025] In addition, this embodiment is equipped with a recovery tool 3 that reaches the core sampler 2 through the communicating space by pressure pumping and recovers the core sampler 2, and the recovery tool 3 is equipped with a centralizer 34 that abuts against the wall surface of the communicating space and supports the recovery tool 3 at its axis. With this configuration, the centralizer 34 ensures a space between the outer periphery of the body portion 32 and the inner wall of the hollow rod 50, so that the recovery tool 3 can be smoothly pumped to the position of the core sampler 2.

[0026] The present invention has been described above based on the embodiment. This embodiment is merely an example, and it will be understood by those skilled in the art that various modifications are possible in terms of the combination of the respective components, and that such modifications are also within the scope of the present invention. [Explanation of symbols]

[0027] 1 Rock core sampling system 2 Core Sampler 3 Recovery tool 4 Tunnel Face 5. Drilling Machine 6 Bottom of hole 21 Collection section 22 Spring 23 Fixed part 24 Stopper 25 Spear 31 Cable 32 Torso 33 Latch mechanism 34 Centralizer 50 Hollow Rod 51 Tip Bit 51a aperture 52 Outer perimeter rod 53 Piston

Claims

1. A rock core sampling system for sampling a rock core, comprising: A core sampler is provided in the drilling machine having a communication space leading to the bottom of the hole as a discharge outlet for rock powder drilled at the bottom of the hole, and the core sampler is configured to collect the rock core as the drilling machine drills the hole; A rock core sampling system, characterized in that the core sampler is installed on the tip bit of the drilling machine through the communicating space by pressure feeding.

2. The core sampler comprises: A sampling unit installed on the tip bit of the drilling machine; A fixing part that is fixed to the communication space of the drilling machine and supports the sampling part axially movably via a spring, 2. The rock core sampling system according to claim 1, wherein a slit is formed at an end of the fixing portion that abuts against the spring, the slit opening toward a surface that abuts against the spring.

3. a recovery tool that reaches the core sampler through the communication space by pressure feeding and recovers the core sampler; 3. The rock core sampling system according to claim 1, wherein the recovery tool includes a centralizer that abuts against a wall surface of the communication space and supports the recovery tool at its axis.

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