JP2011209138A - Apparatus for installing measuring instrument in the ground - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure for easily controlling a direction of a measuring instrument installed in a boring hole, and a method.SOLUTION: An apparatus for installing a measuring instrument in the ground comprises: a base 1 for mounting a measuring instrument 4; and wires 2 and a torsion stop material 3. The three wires 2 are made to pass through holes of the wires 2 in the base 1 and the torsion stop material 3. The base 1 is positioned at a position on the same horizontal surface when the wires 2 are suspended vertically, and the torsion stop material 3 is positioned at a position differing from that of the base 1. A direction control material 7 is mounted to the upper end of a group of the wires 2.

Description

  The present invention relates to an apparatus for installing a measuring instrument in the ground.

In order to measure the stress, strain, acceleration, etc. of the ground, a measuring instrument must be installed in the ground.
For such applications, stratified settlement gauges and pipe strain gauges have been developed and used.
In the stratified settlement meter, a hydraulic anchor and a displacement meter are attached to a single rod at an arbitrary interval, which is inserted into a borehole, and the gap between the borehole is filled with a grout material.
This subsidence meter measures the amount of ground rebound and settlement.
The pipe strain gauge is obtained by attaching a strain gauge to a PVC pipe, and is inserted into a boring hole, and a gap between the boring hole is filled with a grout material.
PVC pipes are highly flexible, so if the ground deforms, the PVC pipes will be distorted. It is a device that detects the landslide of the ground by measuring the strain.

JP 2007-205956 A. Japanese Patent Application Laid-Open No. 2007-114079.

The above-described conventional underground instrument installation device has the following problems.
<1> If the subsidence gauge is attached to one rod and inserted to a depth of several tens of meters, the rod will bend and the direction will gradually change within the borehole. It is difficult to correct such a change in direction from the ground.
<2> Since the hydraulic anchor is in close contact with the ground while rotating, the orientation of the measuring instrument cannot be controlled.
<3> Moreover, since this subsidence meter is a device for measuring the vertical displacement of the ground, it is not suitable for measuring strain components (X, Y, Z) of the ground.
<4> Pipe strain gauges can be installed deep underground by adding PVC pipes. However, the more pipes that are added, the easier it is for the instrument to deviate and the vertical accuracy of the PVC pipe also decreases.
<5> Pipe strain gauges can be used to measure large-scale deformations such as landslides because a strain gauge is attached to a PVC pipe that has different deformation characteristics from the ground. It is difficult to measure.

In order to solve the above-described problems, the underground measuring instrument installation apparatus of the present invention includes a measuring instrument mounting base, a wire, and an anti-twisting material. The stopper is installed on the same horizontal plane when the wire is vertically suspended, the stopper is positioned in a plurality of stages, and the platform is positioned on the stopper. The twist-preventing material is positioned below the stopper, and a direction control material is attached to the upper end of the wire group.
Further, the direction control material is constituted by three sub-pipes attached in parallel around the main pipe.
In addition, the method of installing the measuring instrument in the ground according to the present invention uses the above-described device, mounts the measuring instrument on the base plate, hangs it in the borehole, and positions the wire from the ground by the direction control material. It is characterized by performing the adjustment.
The method of installing the measuring instrument in the ground according to the present invention includes mounting the core collected on site on the platform, attaching the measuring instrument to the core, suspending it in the borehole, and using the direction control material from the ground. It is characterized by adjusting the position of the wire.

Since the underground instrument installation device according to the present invention is as described above, the following effects can be obtained.
<1> Since the installation depth and installation orientation of the measuring instrument can be controlled from the ground, the measuring instrument can be installed at an arbitrary depth and arbitrary orientation in the ground.
<2> Therefore, not only the amount of displacement at an arbitrary position, but also stress, strain, acceleration, and the like at that position can be accurately measured.
<3> Especially in the measurement of ground having anisotropy, the installation orientation is important together with the installation depth, but it can meet the demand.
<4> Installation in the hole does not depend on a PVC pipe or the like, and is performed with a wire. Since the entire weight acts on the wire, the wire naturally maintains verticality and does not bend like a PVC pipe.
<5> If the measuring instruments are installed at a plurality of positions on the wire, the measuring instruments can be installed in multiple depths and multiple directions by one boring hole.

The perspective view of the Example of the measuring device installation apparatus to the underground of this invention. The side view of the Example of the measuring device installation apparatus in the ground. The perspective view of the Example of a direction control material. Explanatory drawing of implementation which mounts a core in a base and installs it in the ground. Explanatory drawing of the state installed in the ground.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

<1> Overall configuration.
The underground measuring instrument installation device of the present invention includes a platform 1 for mounting the measuring instrument 4, a wire 2, and an anti-twisting material 3.
Hereinafter, individual members, their relations, and usage methods will be described.

<2> Base board.
In the embodiment shown in the figure, the base plate 1 is a case where it is constituted by a circular thin plate.
However, the base plate may be any one that can exhibit the function of mounting or attaching a measuring instrument, a core, or the like as will be described later.
Therefore, the shape is not limited to a plate shape, and may be a ring shape, a net shape, a polygonal shape or the like as long as it has a predetermined strength, and may be of any shape or size.
Particularly in the case of a ring shape, a net shape, or a frame shape, it is advantageous because it does not become the resistance of water or filler in the bore hole.
A commercially available measuring instrument 4 or, for example, a core 5 already collected is mounted on the base plate 1.
Here, the “core” is a columnar body of the ground cut by the core boring performed before the installation of the measuring instrument 4.
When the sensor is attached to the core 5 and the core 5 is suspended in the boring hole and returned to the position before cutting, the measurement is performed before the boring hole is filled with mortar. It is possible to obtain highly accurate measurement values close to the local board.
However, the application of the present invention is not limited to such a case, and various commercially available measuring instruments 4 that require specification of the orientation can be mounted and used.
The base plate 1 is opened with three through holes, and a wire 2 described later is passed therethrough.
When it is desired to install the measuring instruments 4 at a plurality of locations, the platform 1 is arranged at a plurality of positions along the wires 2.

<3> Wire.
In the apparatus of the present invention, three wires 2 are used.
Since the posture of the base plate 1 cannot be maintained with two wires 2 and it is difficult to apply a load evenly with four wires, three wires are selected.
The length of the wire 2 is longer than the depth of the boring hole, but if it is shorter, the turn 2 is interposed to adjust the elongation of the wire 2 and the manufacturing error so as to keep the position of the base 1 accurately.
The signal line of the measuring instrument 4 mounted on the base board 1 is guided along the wire 2 to the ground part.

<4> Stand and wire.
The base 1 and the wire 2 are attached via a stopper 6 attached to the wire 2.
Although this stopper 6 is attached to each wire 2, it installs in the position of the same horizontal surface when three wires 2 are suspended vertically.
Then, the base 1 is positioned on the stopper 6.
Since the heavy measuring instrument 4 and the core 5 are mounted on the base 1, the base 1 does not slide upward.
By installing the platform 1 in a plurality of stages, the measuring instruments 4 can be installed in multiple depths and multiple directions by one boring hole.

<5> Measurement of displacement in the tilt direction.
The plurality of stoppers can be arranged at different heights instead of being positioned on the same horizontal plane.
As a result, the measuring instrument is not limited to be horizontal but is installed at an angle, and measurement in an oblique direction can be performed.
In that case, it is possible to set not only the horizontal “azimuth” but also the tilt of the platform (an oblique angle in the vertical direction) to an arbitrary tilt angle by separately operating the three wires up and down. it can.

<6> Anti-twist material.
The anti-twist material 3 is a member for preventing the occurrence of a phenomenon that the three wires 2 are twisted or entangled.
For this purpose, a thin disk similar to the above-described base plate 1 is used, and through holes are penetrated from the front surface to the back surface at three locations.
Since this anti-twisting material 3 is a member for preventing the twisting of the three wires 2 and the like, it is not necessary to be a disk, and it is sufficient if the distance between the three wires 2 can be maintained. It is also possible to employ a member that is formed in a regular triangle.
Further, the anti-twist material 3 is made of a material having a small specific gravity so as to be pushed up by water or a filler in the boring hole.
The installation position of the anti-twist material 3 varies depending on the length, diameter, and rigidity of the wire 2, but is arranged at one or a plurality of positions where the twist of the wire 2 can be prevented.

<7> Anti-twist material and wire.
The anti-twist material 3 and the wire 2 are attached via a stopper 6 attached to the wire 2.
As described above, the stopper 6 is attached to each wire 2, but is installed at a position on the same horizontal plane when the three wires 2 are suspended vertically.
Then, the twist preventing material 3 is positioned under the stopper 6.
Therefore, although the twist preventing material 3 is lowered along the wire 2, it is pushed up by the water or the filling material filled in the boring hole, so that it remains at the position of the stopper 6.

<8> Direction control material.
A direction control member 7 is attached to the upper end of the group of wires 2.
Since the direction control member 7 only needs to support the upper ends of the three wires 2, for example, it may be a disk similar to the anti-twist member 3 or a rod-like body such as a reinforcing bar formed in a triangle.
In the embodiment of FIG. 3, the main pipe 71 is located at the center of the direction control member 7, and three sub pipes 72 are equally distributed around the periphery and attached in parallel.
The diameter of the main pipe 71 is smaller than the outer diameter of the base plate 1 and the anti-twisting material 3, and the position of the sub pipe 72 is formed to coincide with the position of the wire 2.
The signal line of the measuring instrument 4 is passed through the main pipe 71, and the wire 2 is passed through the sub pipe 72.
Therefore, the sub pipe 72 needs to be installed in parallel with the central axis of the main pipe 71 accurately.
If comprised in this way, the operation | work which changes the position of the wire 2 by moving a position using the main pipe 71 or the subpipe 72 is easy.

<9> Temporary fixing.
The direction control material is temporarily fixed at the upper end of the anchor hole so that it does not fall into the anchor hole.
For this purpose, an elongate member that is sufficiently longer than the diameter of the hole is disposed horizontally at the upper end of the anchor hole in the direction crossing the hole.
A member that fulfills such a function is usually referred to as “Kanshikashi 8”. If the direction control member 7 is straddled on this Kanzashikushi 8, the wire 2 is extended, the stopper 6 is installed, and twisted. The fitting operation of the stopper 3 and the filling operation of the filler can be performed safely.

<10> Installation in the borehole. (Fig. 5)
First, a boring hole 9 is opened in order to install the measuring instrument 4 in the ground.
And the apparatus of this invention is suspended in the inside of the boring hole 9 filled with water or a filler.
For this purpose, the upper end of the wire 2 is supported by a crane, manpower, or an assembled tower hoist.
A measuring instrument 4 such as an accelerometer is mounted on the base plate 1, and a filling hose is attached to the wire 2 and suspended toward the hole bottom of the boring hole 9.
Then, the verticality can be secured naturally by gravity, and it does not bend in the middle like the conventional method of inserting several tens of meters of PVC pipe.
Furthermore, the torsion stopper 3 having a small specific gravity is pushed up to the position of the stopper 6 and is positioned at a predetermined height.

<11> Orientation control.
Since the wire 2 can naturally ensure verticality, the position of the three wires 2 can be changed by rotating the direction control member 7 located at the upper end of the group of wires 2 around the vertical line.
Therefore, the measuring instrument 4 having a fixed direction can be installed in the ground with an accurate orientation.
It is a feature of the present invention that the maintenance and securing of such directionality in the ground can be easily performed without using a precise and expensive gyroscope.
When the measuring instrument 4 is installed at the depth intended for measurement in the correct direction, a solidified filler such as mortar is injected from the bottom of the hole through a pipe inserted into the borehole 9.
When the filler is solidified, the upper end of the wire 2 is opened, and the crane and the tower are removed.

<12> In-situ installation of the core.
In order to know the strain characteristics of the ground with anisotropy, it is necessary to obtain the three-dimensional strain of the in-situ ground.
In that case, as shown in FIG. 4, the core 5 collected by boring can be mounted on the base 1 and suspended to the original position.
Then, a sensor such as a strain gauge is attached to the core 5 and a signal is taken out.
As described above, according to the apparatus of the present invention, the direction of the core 5 can be controlled on the ground to accurately match the original position ground, and various measurements can be performed in this state.
Thereafter, mortar is injected from the bottom of the ring hole 9.

1: Base 2: Wire 3: Torsion stop material 4: Measuring instrument 5: Core 6: Stopper 7: Direction control material 8: Kanzashi muscle 9: Boring hole

Claims (5)

A platform for mounting the instrument,
Composed of wire and anti-twist material,
Three wires are inserted through the wire hole between the base and the anti-twist material,
Place the platform at the same horizontal plane when the wire is vertically suspended,
Position the anti-twist material at a different position from the base,
A direction control material is attached to the upper end of the wire group.
Instrument installation device in the ground.
A platform for mounting the instrument,
Composed of wire and anti-twist material,
Three wires are inserted through the wire hole between the base and the anti-twist material,
Install a stopper on the same horizontal plane when the wire is suspended vertically,
Position this stopper in multiple stages,
Place the base on the stopper,
The anti-twist material is located under the stopper,
A direction control material is attached to the upper end of the wire group.
Instrument installation device in the ground.
The direction control material according to claim 1 or 2,
Consists of three sub-pipes attached in parallel around the main pipe,
Instrument installation device in the ground.
Using the device according to claim 1 or 2,
Mount a measuring instrument on the above platform and hang it in the borehole,
Adjust the position of the wire from the ground with the direction control material,
How to install measuring instruments in the ground.
Using the device according to claim 1 or 2,
The core collected on-site is mounted on the above platform,
Attach a measuring instrument to the core and hang it in the borehole.
Adjust the position of the wire from the ground with the direction control material,
How to install measuring instruments in the ground.

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