JP5223622B2 - Measuring instrument holding jig, installation method of measuring instrument - Google Patents

Description

  The present invention relates to a measuring instrument holding jig for holding a measuring instrument such as an AE sensor in contact with an inner peripheral surface of a hole excavated in the ground.

  When excavating the ground to build a tunnel, etc., stress redistribution occurs in the ground, and new cracks occur or cracks progress, resulting in decreased adhesion and openings in the ground. (In this application, this phenomenon is called "slack"). When the stress is redistributed in the ground as described above, the strain energy stored in the ground is released, and acoustic emission (hereinafter referred to as AE) is generated. Conventionally, the occurrence of ground looseness is detected by observing such AE.

  Here, the AE sensor for observing AE must be arranged in the ground in a state where vibrations in the ground can be detected. For this reason, conventionally, a method of forming a drilling hole in the ground, placing a measuring instrument in the drilling hole, filling the drilling hole with mortar, etc., and fixing the measuring instrument (hereinafter referred to as a burying method) Is used.

Further, the applicants of the present application, using an AE sensor placement jig provided with an air cylinder for projecting the AE sensor toward the outer periphery, insert the placement jig into a drilling hole formed in the ground, A method of bringing the AE sensor into contact with the inner peripheral surface of the excavation hole by sending gas into the air cylinder with an air compressor has been proposed (for example, see Patent Document 1).
Japanese Patent No. 3161976

  However, in the above burying method, the AE sensor cannot be recovered and reused after the construction of the tunnel or the like is completed. For this reason, there is a problem that an expensive AE sensor is required every time construction is performed, resulting in high costs.

  Moreover, in the method using the arrangement jig provided with the air cylinder, when the measurement is performed for a long period of time, the state in which the gas is fed into the air cylinder must be maintained. However, even if an attempt is made to keep the gas fed to the air cylinder by the air compressor, the gas cannot escape completely and the gas escapes. For this reason, when time passes, there exists a problem that the force which presses an AE sensor will become weak.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for collecting a measuring instrument after measurement and holding the measuring instrument suitable for long-term measurement in a borehole. It is to be.

  The measuring instrument holding jig of the present invention is a measuring instrument holding jig for disposing a measuring instrument in a drilling hole excavated in a rock, and is formed in a cylindrical shape, and an opening communicating with the internal space is formed on a side surface. A jig body, a pedestal part to which the measuring instrument is attached and disposed at a position corresponding to the opening in the internal space of the jig main body, and the pedestal part so that the measuring instrument protrudes from the opening of the jig main body A pair of cylinders that are arranged on both sides in the axial direction of the jig main body of the pedestal portion, the rod moves in a direction away from the pedestal portion by supplying pressure, and one end of the cylinder A pedestal portion, and a pair of connecting members whose other ends are rotatably connected to the rods of the pair of cylinders, respectively, and in the state where the measuring instrument protrudes from the opening of the jig body, the connecting member is , Contact with the rod Than parts, characterized in that towards the connecting portion between the pedestal portion is inclined with respect to the axial direction of the jig main body such that the opening side.

In the above-described measuring instrument holding jig, the jig main body may include a guide portion that protrudes toward the outer periphery and has a guide roller attached to the tip thereof.
The cylinder is normally in a state in which the rod has advanced, and is composed of a hydraulic cylinder or a pneumatic cylinder in which the rod retreats when pressure is supplied, and the rod is placed in the inner space of the jig main body on the pedestal side. It may be attached so that it may be located in.

  Further, the measuring instrument installation method of the present invention is a method of installing a measuring instrument in an excavation hole by using the measuring instrument holding jig, and the measuring instrument is attached to the pedestal portion of the measuring instrument holding jig. In a state where pressure is supplied to the cylinder, the measuring instrument holding jig is inserted into the excavation hole, and the pressure is removed from the cylinder.

  According to the present invention, when installing or removing the measuring instrument, by supplying pressure to the cylinder, the end of the connecting member connected to the cylinder is drawn toward both ends of the jig body, and the pedestal is opened. Therefore, the measuring instrument is accommodated in the jig body. Moreover, by removing the pressure from the cylinder at the time of measurement, the pedestal portion is pressed by the pressing means, and the measuring instrument protrudes from the opening. With such a configuration, the measuring instrument can be recovered after the measurement is completed, and the measuring instrument can be pressed against the inner wall surface of the excavation hole with a constant force even during a long-term measurement, thereby performing stable measurement. Can do.

Hereinafter, an embodiment of a measuring instrument holding jig of the present invention will be described in detail with reference to the drawings. In the following description, an example in which an AE sensor is installed in an excavation hole excavated in the ground and an AE wave is measured will be described.
1 and 2 are diagrams showing the configuration of the measuring instrument holding jig 10 according to the present embodiment. FIG. 1 and FIG. 2 are arranged in the excavation hole 110 and measure the AE wave. The holding jig 10 is shown, and the measuring instrument holding jig 10 in a state of being inserted into or removed from the excavation hole 110 is shown. In each figure, (A) is a horizontal cross-sectional view, (B) is a cross-sectional view along BB 'in (A), (C) is an enlarged view of part C in (A), and (D) is in (B). It is an enlarged view of D section.

  As shown in FIGS. 1 and 2, the measuring instrument holding jig 10 of the present embodiment includes a jig main body 20 having an intermediate portion formed in a cylindrical shape and an opening formed on a side surface, and the center of the internal space of the jig main body 20. The pedestal portion 30 to which the AE sensor 1 is attached, the spring member 60 that presses the pedestal portion 30 toward the opening 20A, and the longitudinal direction both sides of the jig body 20 of the pedestal portion 30 are arranged to extend in the axial direction. A pair of pneumatic cylinders 40, rods 41 of the pneumatic cylinders 40 at both ends, and a connection member 50 that is rotatably connected to the pedestal portion 30 are configured.

  The jig main body 20 is formed in a cylindrical shape, and is connected to both ends of the central cylindrical portion 21 having an opening 20A formed substantially in the center in the axial direction, and a circular shape at the end opposite to the central cylindrical portion 21. It consists of the connection part 22 to which the annular connection board 23 was attached. A guide portion 70 is provided on the outer peripheral surface of the connection portion 22 so as to protrude toward the outer periphery and to which a guide roller 71 is attached at the tip.

  The opening 20 </ b> A formed in the central cylindrical portion 21 has a diameter that allows the AE sensor 1 to be inserted substantially without a gap. The internal space of the central cylindrical portion 21 and the internal space of the connection portion 22 communicate with each other, and the conductive wire 80 extending from the AE sensor 1 extends to the end of the connection portion 22 through this communication portion.

The spring member 60 generates a biasing force that presses the AE sensor 1 via the pedestal 30 so that the AE sensor 1 is pushed out through the opening 20A of the jig body 20.
The pneumatic cylinder 40 is normally in a state in which the rod 41 has advanced, and when the air pressure is supplied through the hose 81 extending from the outside, the rod 41 retreats in a direction away from the pedestal portion 30.

  The connection member 50 is connected to the pneumatic cylinder 40 at the end connected to the pedestal 30 in a state where the pedestal 30 is pressed by the spring member 60 and the AE sensor 1 protrudes from the opening 20A of the jig body 20. It attaches in the state inclined so that it might be located in the opening 20A side rather than the edge part of the done side.

  As shown in FIG. 1, since the rod 41 of the pneumatic cylinder 40 is always advanced toward the pedestal portion 30 and the AE sensor 1 is pressed by the spring member 60, the AE sensor 1 is attached to the jig body 20. Projecting outward from the opening 20A.

  On the other hand, as shown in FIG. 2, when air pressure is supplied to the pneumatic cylinder 40 to retract the rod 41, the connecting member 50 is drawn toward the pneumatic cylinder 40. Thereby, the base member 30 presses the spring member 60 by rotating the connecting member 50 in the direction away from the opening 20A around the end connected to the pneumatic cylinder 40. The AE sensor 1 protruding from the opening 20 </ b> A of the jig body 20 is accommodated in the jig body 20.

  In this state, when the air pressure of the pneumatic cylinder 40 is removed, the rod 41 advances toward the pedestal portion 30, and the pedestal portion 30 is pressed toward the opening 20A by the restoring force of the spring member 60. The sensor 1 protrudes from the opening 20A.

Hereinafter, a method for installing the AE sensor 1 in the excavation hole and a method for removing the AE sensor 1 using the measuring instrument holding jig 10 will be described.
As shown in FIG. 3, when the measuring instrument holding jig 10 is installed in the excavation hole 110, first, the preamplifier apparatus 200 in which the preamplifier is installed is connected to the measuring instrument holding jig 10. The connecting member 210 is connected to.
The preamplifier device 200 includes a cylindrical accommodating portion 201 and a connecting portion 202 connected to both ends of the accommodating portion 201 and having a connection plate 203 attached to the end portion. The preamplifier is accommodated in the accommodating portion 201. . The connection member 210 is formed by connecting a connection plate 211 to an end portion of a tubular member.

  The measurement holding jig 10 and the preamplifier device 200 are connected by bolting the respective connection plates 23 and 203. Similarly, the preamplifier device 200 and the connection member 210 are connected by bolting the connection plates 203 and 211, respectively.

  Further, the conductive wire 80 extending from the AE sensor 1 is connected to the preamplifier through the inside of the preamplifier device 200, and the conductive wire extending from the preamplifier is connected to the AE measuring device 220 installed outside through the inside of the connection member 210. Further, the hose 81 extending from the pneumatic cylinder 40 is connected to the air compressor 230 installed outside through the connection member 210 and the preamplifier device 200.

  Next, compressed air is supplied to the pneumatic cylinder 40 by the air compressor 230. Thereby, as described with reference to FIG. 2, the rod 41 of the pneumatic cylinder 40 is retracted, and the AE sensor 1 protruding from the opening 20 </ b> A is accommodated in the jig body 20. While maintaining this state, the measuring instrument holding jig 10 is inserted into the excavation hole 110 excavated in the ground 130. At this time, the jig body 20 can be smoothly inserted into the excavation hole 110 by the guide roller 71 of the guide unit 70 coming into contact with the inner peripheral surface of the excavation hole 110.

  Then, the air pressure of the pneumatic cylinder 40 is removed with the AE sensor 1 reaching a predetermined position. Thereby, as described with reference to FIG. 1, the rod 41 of the pneumatic cylinder 40 is opened, and the pedestal 30 is biased by the spring member 60, whereby the AE sensor 1 protrudes to the outside through the opening 20A. It will be pressed against the inner peripheral surface of the excavation hole 110. In this state, the AE measuring device 220 measures the AE wave.

  When the measurement of the AE wave is completed, the compressed air is supplied to the pneumatic cylinder 40 by the air compressor 230 again. Thereby, as described with reference to FIG. 2, the rod 41 of the pneumatic cylinder 40 is retracted, and the AE sensor 1 protruding from the opening 20 </ b> A is accommodated in the jig body 20. With this state maintained, the measuring instrument holding jig 10 is removed from the excavation hole 110 to the outside.

  According to this embodiment, since the measuring instrument holding jig 10 can be collected from the excavation hole 110 after the measurement of the AE wave is completed, the AE sensor 1 and the measuring instrument holding jig 10 can be reused. Compared with the method of burying and killing the AE sensor 1, the cost can be reduced. Further, even when a failure occurs in the AE sensor 1, it can be immediately recovered and repaired.

  When measuring the AE wave, the air pressure of the pneumatic cylinder 40 is removed, and the measurement is performed in a state where the spring member 60 presses the AE sensor 1 against the inner peripheral surface of the excavation hole 110. For this reason, even if it is a measurement over a long period of time, a stable measurement can be performed without changing the force for pressing the AE sensor 1 against the inner peripheral surface of the excavation hole 110. In addition, since it is not necessary to supply air pressure during measurement, it does not take time for measurement.

  Further, even when blasting vibration due to blasting for excavating the ground is received during measurement, the AE sensor 1 can absorb the blasting vibration by the spring member 60, so that the AE sensor 1 is the inner peripheral surface of the drilling hole 110. There is no fear of coming off.

  In this embodiment, the case where the AE sensor 1 is disposed in the excavation hole 110 has been described. However, the present invention is not limited to this, and a measuring instrument that performs measurement in close contact with the ground such as an accelerometer, a displacement meter, and a thermometer. If so, the measuring instrument holding jig of the present invention is applied.

In the present embodiment, the pneumatic cylinder 40 in which the rod 41 retracts when pneumatic pressure is supplied is used. However, the pneumatic cylinder is not limited to this, and the pneumatic cylinder advances when the pneumatic pressure is supplied. It is also possible to use. In such a case, the cylinder rod may be attached so as to be positioned at both ends of the jig body.
In the present embodiment, the pneumatic cylinder 40 is used. However, the present invention is not limited to this, and a hydraulic cylinder can also be used.

The measuring instrument holding jig which is arrange | positioned in an excavation hole and in the state which measures an AE wave is shown, (A) is a horizontal sectional view, (B) is a BB 'sectional view in (A), (C) is ( The enlarged view of the C section in A), (D) is the enlarged view of the D section in (B). The measuring instrument holding jig in the state of being inserted into or removed from the excavation hole is shown, (A) is a horizontal cross-sectional view, (B) is a cross-sectional view along BB 'in (A), (C) is The enlarged view of the C section in (A), (D) is the enlarged view of the D section in (B). It is a figure which shows a mode that a measuring instrument holding jig is installed in a digging hole.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 AE sensor 10 Measuring instrument holding tool 20 Jig body 20A Opening 21 Central cylindrical part 22 Connection part 23 Connection board 30 Pedestal part 40 Pneumatic cylinder 41 Rod 50 Connection member 60 Spring member 70 Guide part 71 Guide roller 80 Conductor 81 Hose 110 Drilling hole 130 Ground 200 Preamplifier device 220 AE measuring device 230 Air compressor

Claims (4)

A measuring instrument holding jig for placing a measuring instrument in an excavation hole excavated in a rock,
A jig body formed in a cylindrical shape and having an opening communicating with the internal space on the side surface;
The measuring instrument is mounted, and a pedestal portion disposed at a position corresponding to the opening of the internal space of the jig body,
A pressing means for pressing the pedestal so that the measuring instrument protrudes from the opening of the jig body;
A pair of cylinders arranged on both sides of the jig body of the pedestal portion in the axial direction and supplied with pressure so that the rod moves in a direction away from the pedestal portion;
A pair of connection members, one end of which is connected to the pedestal portion and the other end of the pair of cylinders are rotatably connected to the rods of the pair of cylinders,
In the state where the measuring instrument protrudes from the opening of the jig main body, the connecting member is connected to the pedestal portion so that the connecting portion to the base portion is closer to the opening side than the connecting portion to the rod. An instrument holding jig characterized by being inclined with respect to the axial direction. The measuring instrument holding jig according to claim 1,
A measuring instrument holding jig, wherein the jig main body includes a guide portion that protrudes toward an outer periphery and has a guide roller attached to a tip thereof. The measuring instrument holding jig according to claim 1 or 2,
The cylinder is normally in a state where the rod has advanced, and is composed of a hydraulic cylinder or a pneumatic cylinder in which the rod retreats when pressure is supplied, and the rod is positioned in the inner space of the jig main body on the pedestal side. A measuring instrument holding jig, which is attached so as to perform. A method of installing a measuring instrument in an excavation hole using the measuring instrument holding jig according to any one of claims 1 to 3,
The measuring instrument is attached to the pedestal of the measuring instrument holding jig,
With the pressure supplied to the cylinder, the measuring instrument holding jig is inserted into the excavation hole,
A method for installing a measuring instrument, wherein pressure is removed from the cylinder.

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