JP2017115390A - Working face front probing device and working face front probing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and accurately probe a state of a bed lock by directly photographing an inner surface (bore wall) of a boring hole having been drilled in almost horizontal direction as a state of bare hole when probing the state of the bed lock in front of a tunnel working face.SOLUTION: A working face front proving device includes a boring hole 10 drilled almost in horizontal direction to the front of a working face, a packing material 20 which is translucent and is packed in the boring hole 10, a bore hole camera 30 capable of being inserted in the boring hole 10, and a display device 50 which displays an image taken with the bore hole camera 30. The bore hole camera 30 is preferred to be set at a tip end part of a hollow pipe (support rod 40).SELECTED DRAWING: Figure 2

Description

  The present invention relates to a face front exploration device and a face front exploration method, and more particularly to an apparatus and method for exploring natural ground in front of a tunnel face by inserting a borehole camera into a horizontal borehole.

  When performing civil engineering work, it is necessary to conduct ground exploration in order to grasp the ground state in advance. For example, when performing tunnel excavation, in order to perform safe, appropriate, and rapid construction, it is necessary to grasp the state of natural ground prior to tunnel excavation or according to the progress of tunnel excavation. Conventionally, various techniques for exploring natural ground have been proposed. As such a prior art, there is a direct method by boring (hole drilling method, advanced boring). Indirect methods include elastic wave exploration by the reflection method (HSP method, TSP method, reflection tomography) and the like.

  In addition, in order to grasp the situation in the borehole drilled in the vertical direction, there is a method of taking an internal image by inserting a borehole camera into the borehole. Various techniques for observing an inner surface of a boring hole drilled in a vertical direction or an inter-hole joint built in a vertical direction with a borehole camera are disclosed (see Patent Document 1). The in-pipe imaging device described in Patent Literature 1 includes a borehole camera for photographing the inside of the tube, and a capsule that includes the borehole camera in a watertight manner and has a transparent surface in the imaging direction. This in-pipe imaging device takes a picture of the inside of a joint pipe by inserting a transparent capsule containing a borehole camera in a watertight manner into the joint pipe to a predetermined depth and removing muddy water (turbid water) filled in the joint pipe by the width of the capsule. You can do that.

  In addition, in order to explore the ground condition (geological structure etc.) in front of the face of the tunnel, a technique has been disclosed in which a borehole camera is inserted into a borehole drilled in a substantially horizontal direction to capture an internal image ( Patent Document 2). In the exploration method of a natural ground / geological structure in front of a face of a tunnel described in Patent Document 2, a drilling hole is formed using a transparent pipe member in a relay pipe of a drilling machine. A borehole camera is inserted into the transparent tube member, and the situation of the natural ground is photographed through the tube member.

JP 2005-201717 A JP 2012-12879 A

  The technique described in Patent Document 1 described above is a technique for inserting a borehole camera into a joint pipe installed in a vertical direction and shooting an image in the joint pipe. The borehole camera is suspended and inserted in the vertical direction. Therefore, when the borehole camera is inserted or removed, the possibility that the borehole camera is caught on the inner surface (hole wall) of the joint pipe is extremely low.

  On the other hand, in the case of a bored hole (bare hole) drilled in the horizontal direction, the borehole camera may be caught by cracks or protrusions on the hole wall, which may not only be difficult to insert, Even if it can be done, there is a possibility that it cannot be collected. In this regard, in the technology described in Patent Document 2, a transparent tube member is used for the relay tube of the hole drilling machine, and a borehole camera is inserted into the tube member to perform photographing. The possibility of being caught is low.

  However, the technique described in Patent Document 2 photographs the inner surface (hole wall) of the borehole by installing a transparent tube member in the borehole. Therefore, since the hole wall is protected by the pipe member, the actual geology may not be grasped from the captured image. Moreover, since the pipe member uses acrylic resin, polycarbonate resin, vinyl chloride resin, or the like, the outer surface thereof is scratched, and in the worst case, the pipe member may be damaged. If the outer surface of the tube member is scratched or damaged, the image may become unclear or may not be photographed.

  The present invention has been proposed in view of the above-described circumstances, and when exploring the ground condition in front of a tunnel face, the inner surface (hole wall) of a bored hole drilled in a substantially horizontal direction is directly in a bare hole state. An object of the present invention is to provide a face front exploration device and a face front exploration method capable of easily and accurately exploring natural ground conditions by photographing.

  The face forward exploration device and the face forward exploration method of the present invention have the following features in order to achieve the above-described object. In other words, the face front exploration device of the present invention is a device for exploring the ground condition in front of the tunnel face, and a boring hole drilled in a substantially horizontal direction toward the front of the face, and filled in the bore hole. It is characterized by comprising a translucent filler, a borehole camera that can be inserted into a borehole, and a display device that displays an image taken by the borehole camera.

  In addition to the above-described configuration, the borehole camera is preferably installed at the tip of the hollow tube.

  The face front exploration method of the present invention is a method for exploring the ground condition in front of a tunnel face, and drills a borehole in a substantially horizontal direction toward the front face of the face, and makes the borehole translucent. The borehole camera is inserted, the inner wall surface of the borehole is photographed, and the image taken by the borehole camera is displayed on the display device to analyze the geology of the ground in front of the face. Is.

  In the face front exploration device and the face front exploration method according to the present invention, a hole retaining tube is formed by filling a filler (for example, a gel-like substance) into a horizontal boring hole drilled toward a natural ground in front of the face. It is possible to maintain the bare hole state without using the like, and to directly photograph the inner surface (hole wall) of the borehole in this state.

  Therefore, it is possible to easily and accurately search the ground condition compared to photographing through a hole-holding tube or the like. In addition, since the filling material (eg, a gel-like substance) filled in the horizontal boring hole is higher in viscosity than water, it does not leak out from the hole of the horizontal boring hole by performing appropriate leakage prevention. .

The schematic diagram which shows the structure of the borehole camera used with the face front search apparatus which concerns on embodiment of this invention. The schematic diagram which shows the installation state of the face front exploration apparatus which concerns on embodiment of this invention. Explanatory drawing which shows the procedure of the face front search method which concerns on embodiment of this invention.

  Hereinafter, with reference to the drawings, an embodiment of a face forward exploration device and a face forward exploration method according to the present invention will be described. FIGS. 1 to 3 are diagrams for explaining a face front exploration device and a face front exploration method according to an embodiment of the present invention. FIG. 1 is a schematic diagram showing a configuration of a borehole camera, and FIG. 2 is an installation state of the face front exploration device. FIG. 3 is an explanatory diagram showing the procedure of the method for exploring the front of the face.

<Overview of the face front exploration device and face front exploration method>
The face front exploration device and face front exploration method according to the embodiment of the present invention is a technique for directly exploring a ground condition in front of a face using a borehole camera 30, as shown in FIG. A substantially horizontal boring hole 10 is drilled in the front ground, and a filling material 20 having translucency is filled in the boring hole 10, and a borehole camera 30 is inserted to form an inner surface (hole wall) of the boring hole 10. ) To investigate the condition of the natural ground (geology, etc.). The face forward exploration device of the present invention displays a borehole 10 and a translucent filler 20 filled therein, a borehole camera 30 that can be inserted into the borehole 10, and an image taken by the borehole camera 30. And a display device 50.

<Borehole camera>
As shown in FIG. 1, the borehole camera 30 is a camera for photographing internal images of the borehole 10 and the hollow pile, and a commercially available one can be used. As shown in FIG. 1, the borehole camera 30 includes a housing 31, an imaging lens system 32, an imaging element 33, and an illumination device 34 as a basic configuration. Furthermore, a mirror 35 for bending imaging light from the imaging surface may be provided in order to perform lateral imaging, and the mirror 35 may be an attachment member that can be attached to and detached from the housing 31. Further, a zooming mechanism, a focus mechanism, a pan / tilt mechanism, and the like may be provided.

  The imaging light that has entered the imaging lens system 32 forms an image on the imaging element 33 and is taken into a personal computer (not shown) or the like via the signal cable 36 as a video signal of the imaging target surface. Although not shown, an image of the imaging target surface (in the present invention, the inner surface (hole wall) of the boring hole 10) is displayed by the display device 50 connected to a personal computer.

<Boring hole>
The boring hole 10 is drilled substantially horizontally toward the front of the face. Note that “substantially horizontal” means not only a completely horizontal state but also a state in which a slight inclination is allowed. The number of drilling holes in the borehole 10 is not particularly limited, but an appropriate number is drilled according to the size of the tunnel cross section, the bending state of the tunnel, the condition of the natural ground previously known, and the like. In order to form the boring hole 10, for example, as shown in FIGS. 3A to 3C, the hollow rod may be inserted into the natural ground while supplying water from the tip of the hollow rod.

<Filler>
The filler 20 has translucency, and by filling the bore hole 10, the stability of the hole wall is maintained, and the lubricant between the bore hole camera 30 and the hole wall and the bore hole camera 30 are maintained. Acts as a propellant. Moreover, since the filler 20 has translucency, even if it exists between the borehole camera 30 and the hole wall, it does not hinder the photographing of the hole wall. As the filler 20, it is preferable to use a gel-like substance.

<Display device>
The display device 50 is a device for displaying an image captured by the borehole camera 30 and includes a liquid crystal display device (monitor) or the like. Note that the printer functions as the display device 50 when printing an image captured by the borehole camera 30. In other words, an apparatus for displaying an image is an apparatus that can visualize and display an image and is a concept including a monitor, a projection device, a printer, and the like.

<Combination with other exploration methods>
In the face forward exploration device and face forward exploration method of the present embodiment, the video taken by the borehole camera 30 is a main element of the geological analysis. In addition to this, the drilling hole obtained when drilling the horizontal borehole 10 By using logging data, resistivity distribution data, elastic wave velocity distribution data, etc., two or more types of information can be comprehensively evaluated at the same point, and geological prediction in front of the face with higher accuracy. Is possible.

<Procedure of exploration method>
Next, with reference to FIG. 3, an example of the method for exploring the front face of the face according to the present invention will be described. In the face front exploration method of the present invention, the tunnel front exploration device having the above-described configuration is used for exploring the ground condition (geology) in front of the face when excavating a tunnel.

  In the face front exploration method of the present invention, first, a substantially horizontal boring hole 10 is drilled in a natural ground in front of the face. The boring hole 10 is formed by, for example, installing the hollow rod 60 on a natural ground and supplying water from the tip of the hollow rod 60 (a). When the boring hole 10 is drilled to a predetermined length, the water supply is stopped. In this state, the water existing in the borehole 10 escapes from the bedrock crack or the mouth of the hollow rod 60 (b).

  Subsequently, the filler 20 is supplied from the tip of the hollow rod 60 into the boring hole 10 (c), and the hollow rod 60 is pulled out while continuing to supply the filler 20 (d). When the extraction of the hollow rod 60 is completed, the inside of the bore hole 10 is filled with the filler 20 (e).

  Further, the borehole camera 30 is attached to the tip of the support rod 40 made of a hollow PVC pipe or the like. Then, the tip of the support rod 40 to which the borehole camera 30 is attached is inserted into the borehole 10 (f), and the filler 20 is sucked from the borehole 10 through the hollow portion of the support rod 40 and supported. The rod 40 is inserted into the boring hole 10 and installed (g). At this time, suction of the filler 20 generates a negative pressure in the borehole 10, and the support rod 40 to which the borehole camera 30 is attached can be propelled into the borehole 10 due to the friction reducing effect of the filler 20. Yes (h). After the support rod 40 is inserted to a predetermined position on the back side of the borehole 10 (i), the hole wall 30 is photographed with the borehole camera 30 while the support rod 40 is pulled out from the borehole 10 (j). Then, the geology of the ground in front of the face is analyzed based on the video displayed on the display device 50.

DESCRIPTION OF SYMBOLS 10 Boring hole 20 Filler 30 Borehole camera 31 Case 32 Imaging lens system 33 Imaging element 34 Illumination device 35 Mirror 36 Signal cable 40 Support rod 50 Display device 60 Hollow rod

Claims (3)

A device for exploring ground conditions in front of a tunnel face,
A boring hole drilled in a substantially horizontal direction toward the front of the face,
A translucent filler filled in the borehole;
A borehole camera that can be inserted into the borehole;
A display device for displaying images taken by the borehole camera;
A device for exploring the front of the working face. The borehole camera is installed at the tip of a hollow tube,
The face forward exploration device according to claim 1. A method for exploring ground conditions in front of a tunnel face,
Drill a boring hole in the horizontal direction toward the front of the face,
Filling the boring hole with a translucent filler and inserting a borehole camera to photograph the inner wall surface of the boring hole,
Analyzing the geology of the ground in front of the face by displaying on the display device the video taken by the borehole camera.
A method for exploring the front of the face.

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