JP2023008489A - Linear body installation method - Google Patents

Abstract

To efficiently perform positioning of a linear body installed in a ground.SOLUTION: A method for installing a linear body includes: an insertion step in which a diameter expanding body 20 capable of expanding a diameter in a radial direction outside of a boring hole 2 is provided at a tip section, and a rod material 10 to which an optical fiber cable 50 is attached along an axial direction on an outer periphery surface is inserted into a boring hole 2; a tip end fixing step in which the diameter expanding body 20 is radially expanded outward and a tip end of the rod material 10 is fixed relative to the boring hole 2; and a base end fixing step of fixing the base end of the rod material 10 relative to the boring hole 2 at an open end 2b of the boring hole 2.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for installing a linear body in ground.

When constructing a tunnel or an underground cavity, linear objects are sometimes installed in the ground and used to detect the state of the ground. Patent Literature 1 discloses a method of installing an optical fiber cable in the ground as a linear body for measuring ground displacement.

In the method disclosed in Patent Document 1, the outer peripheral surface of the pipe to which the optical fiber cable is attached is stretched in the circumferential direction and the Positioning spacers are provided along the axial direction.

JP-A-2002-156215

In the method disclosed in Patent Document 1, positioning spacers are provided over the area where the optical fiber cables are installed. For this reason, the longer the bore hole, the more positioning spacers need to be attached to the pipe, and the positioning spacers must be attached as evenly as possible in the circumferential and axial directions in order to position the optical fiber cable at a predetermined position. There is a need. Therefore, the number of man-hours required for preparation before inserting the optical fiber cable into the borehole is increased, and as a result, the construction period may be prolonged.

An object of the present invention is to efficiently position a linear body installed in the ground.

The present invention relates to a linear body installation method for installing a linear body in a hole formed in the ground, wherein a diameter expandable body is provided at a distal end portion of the linear body, the diameter of which can be expanded radially outward of the hole, and an outer peripheral surface of the linear body. an inserting step of inserting a bar to which the linear body is attached along the axial direction into the hole; and a base end fixing step of fixing the base end of the bar to the hole at the open end of the hole.

ADVANTAGE OF THE INVENTION According to this invention, positioning of the linear body installed in the ground can be performed efficiently.

FIG. 4 is a diagram showing a linear body installed in a hole by the linear body installation method according to the embodiment of the present invention; It is a figure which shows the linear body installation method which concerns on embodiment of this invention along a time series. FIG. 3 is a diagram showing the linear body installation method according to the embodiment of the present invention continued from FIG. 2 in chronological order; It is a figure which shows the modification of the linear body installation method which concerns on embodiment of this invention.

Hereinafter, a linear body installation method according to an embodiment of the present invention will be described with reference to the drawings.

First, with reference to FIGS. 1 to 3, the process and configuration for installing a linear body in a hole formed in the ground by the linear body installation method according to the embodiment of the present invention will be described. Here, a case where the linear body is an optical fiber cable will be described. In addition to the optical fiber cable, the linear body may be an electric wire or the like, which is a linear member capable of measuring temperature, strain, and the like with high accuracy.

In the construction of civil engineering structures, it is important to understand the state of the ground such as landslides, and it is also important to understand the development of loose areas in the ground caused by excavation of underground cavities such as tunnels, etc. Optical fiber cables are sometimes installed in boreholes drilled into the ground to detect areas of strain or slack in the ground because they are important for drilling in the ground.

An optical fiber cable buried in a borehole is distorted according to the distortion of the ground and the looseness of the ground. be able to.

Specifically, the optical fiber cable has the property of slightly backscattering the incident pulsed light, and by using this property, it is possible to measure the strain at multiple positions in the optical fiber cable. be. Since the frequency of the scattered light depends on the strain of the optical fiber cable, the strain of the optical fiber cable can be measured by injecting the pulsed light into the optical fiber cable and measuring the frequency of the scattered light. In addition, by measuring the time it takes for the scattered light generated in the optical fiber cable to return to the incident position after the pulsed light is incident on the optical fiber cable, the position where the scattered light is generated, that is, the distortion of the optical fiber cable can be measured. The resulting position can be measured.

Therefore, by burying an optical fiber cable in a boring hole dug in the ground and measuring the strain of the buried optical fiber cable, it is possible to measure the strain and loosening of the ground at multiple locations. As a result, the state of the ground can be accurately grasped.

Here, when excavating underground cavities such as tunnels, it is necessary to grasp the state of the ground above and to the sides of the underground cavities. It is formed upward rather than upward or horizontally. In other words, it is necessary to insert the optical fiber cable upward in the vertical direction or upward relative to the horizontal direction before burying it in the boring hole.

However, since optical fiber cables generally tend to flex and are difficult to stand on their own, optical fiber cables are placed over a relatively long distance of 10 m or more in a boring hole that is formed upward in the vertical direction or above the horizontal direction. It is almost impossible to insert it by itself.

In addition, in order to integrate the optical fiber cable with the ground, the boring hole into which the optical fiber cable is inserted is filled with grout such as cement bentonite. It is necessary to fill the drilled borehole with grout against gravity.

Furthermore, even if the borehole into which the optical fiber cable is inserted can be filled with grout, if the optical fiber cable is buried in the borehole in a meandering state, the inner wall surface of the borehole and the optical fiber may be damaged. There will be places where there is almost no gap from the cable and places where the gap is too large. If the distance between the inner wall surface of the borehole and the optical fiber cable varies in this way, the strain transmitted from the natural ground to the optical fiber cable also varies. There is a risk that it will not be possible to accurately grasp the state.

In order to solve such problems, in the linear body installation method according to the present embodiment, as shown in FIGS. After inserting the optical fiber cable 50 (linear body) with the This is done efficiently so that the distance between the inner wall surface of the boring hole and the optical fiber cable does not fluctuate in the axial direction no matter what direction the boring hole 2 is drilled. . FIG. 1 schematically shows a state of an optical fiber cable 50 installed in a boring hole 2 and a holding unit 100 holding a portion of the optical fiber cable 50 by the linear body installation method according to the present embodiment. FIG. 2A to FIG. 2C and FIGS. 3A to 3C are schematic diagrams showing the linear body installation method according to the present embodiment in chronological order.

First, with reference to FIG. 1, an optical fiber cable 50 installed in a borehole 2 and a holding unit 100 for holding the optical fiber cable 50 by a linear body installation method, which will be described in detail later, will be described. In addition, below, the case where the boring hole 2 is excavated upward in the vertical direction will be described.

The holding unit 100 is attached to the bar 10 (pipe material 10) to which the optical fiber cable 50 is attached along the axial direction, and the tip side of the bar 10 (pipe material 10), and is positioned radially outward of the boring hole 2. and a filling hose 30 provided along the bar 10 (pipe material 10). The bar 10 is a long member having an outer diameter sufficiently smaller than the inner diameter of the boring hole 2, and is preferably a hollow pipe 10 as shown in FIG.

The pipe material 10 is a hollow tubular member made of a resin such as polyvinyl chloride, and has an internal passage 11 extending through it in the axial direction. and a communication hole 12 that communicates between the inside and the outside of 10 . The communication hole 12 is formed on the tip side of the pipe material 10 in a state where the holding unit 100 is inserted into the boring hole 2, and in the filling process described later, the air inside the boring hole 2 flows out of the boring hole 2. It functions as an outlet to discharge.

The expanded diameter body 20 includes an expansion portion 22 that expands radially outward according to the pressure of the supplied fluid, a support portion 21 that supports the expansion portion 22 radially inward, and a fluid that is pressurized. and a supply pipe 24 to. FIG. 1 shows a state in which the expanding portion 22 expands radially outward of the boring hole 2 and presses the inner wall surface of the boring hole 2 . In the state in which the inflatable portion 22 is thus inflated, the axial center of the inflatable portion 22 and the axial center of the support portion 21 are substantially aligned and arranged concentrically.

The inflatable portion 22 is a rubber or metal member having a barrel-shaped or cylindrical outer shape, and is a member for supplying fluid to a space (not shown) formed between the support portion 21 and the inflatable portion 22 . It is supported by a support portion 21 so as to expand radially outward according to pressure.

The fluid supplied to the expanded diameter body 20 is, for example, pressurized water, and the expansion portion 22 presses the inner wall surface of the boring hole 2 with a load corresponding to the water pressure. It should be noted that the fluid supplied to the expanded diameter body 20 is not limited to water, and may be compressed air or pressurized hydraulic oil.

The support portion 21 is a cylindrical member having a through hole 21a formed through it in the axial direction, and one end portion in the axial direction is coupled to the tip portion of the pipe member 10 via a coupling member (not shown). By coupling the support portion 21 to the pipe material 10, the through hole 21a of the support portion 21 and the internal passage 11 of the pipe material 10 are in a state of communication.

On the other hand, the other axial end surface 21b of the support portion 21 is pressed against the bottom surface 2a of the boring hole 2 when the holding unit 100 is inserted into the boring hole 2, as shown in FIG. That is, the other axial end surface 21 b of the support portion 21 functions as a restricting surface that restricts the length of the holding unit 100 inserted into the boring hole 2 .

The supply pipe 24 is attached to the pipe material 10 along the axial direction, and one end 24 a of the supply pipe 24 opens into the space formed between the support portion 21 and the expansion portion 22 . The other end 24b of the supply pipe 24 is connected to a fluid supply source such as a pump (not shown) outside the borehole 2 before the pressurized fluid is supplied to the expansion section 22 through the supply pipe 24. When the supply of the fluid to the expansion part 22 is completed, the expansion part 22 is accommodated in the boring hole 2 as shown in FIG. In addition, in order to maintain the expanded state of the expanded portion 22 once expanded, a check valve for preventing reverse flow of the supplied fluid may be provided on the supply pipe 24 .

The filling hose 30 is a hose through which the grout 40 to be filled in the boring hole 2 in the filling process described later flows. installed along. As shown in FIG. 1, the discharge port 30a is positioned vertically below the communication hole 12 formed in the pipe material 10 when the holding unit 100 is inserted into the boring hole 2. As shown in FIG. Note that the discharge port 30a may be arranged vertically below the communication hole 12, and may be arranged near the opening end 2b of the boring hole 2, for example. The other end of the filling hose 30 is connected outside the borehole 2 to a grout delivery pump (not shown).

The optical fiber cable 50 held by the holding unit 100 is a linear member having a flat cross-sectional shape in which a plurality of optical fibers (not shown) and a steel wire are covered with a resin material. 50a is closed with a sealing material such as oil or silicon so that reflection does not occur on the tip end face. By using the optical fiber cable 50 having a flat cross-sectional shape, the optical fiber cable 50 can be laid in a straight line along the surface of the pipe material 10 while avoiding twisting of the internal optical fibers. can.

The tip portion 50a of the optical fiber cable 50 is inserted into the internal passage 11 of the pipe member 10 and the through hole 21a of the support portion 21 through the communication hole 12 formed in the pipe member 10. It is fixed in the vicinity with an adhesive, silicon or the like. The boring hole 2 is drilled to a predetermined depth, and the other axial end face 21b that contacts the bottom surface 2a of the boring hole 2 is located at the deepest part of the boring hole 2. By fixing the tip portion 50a of the cable 50 in the vicinity of the other axial end surface 21b, the tip portion 50a can be used as a reference point when measuring the strain of the ground 1 along the borehole 2.

On the other hand, the other end of the optical fiber cable 50 is connected to the measuring device 60 outside the boring hole 2 .

In order to prevent the closed end portion 50a from being damaged or damaged when the optical fiber cable 50 is inserted into the boring hole 2, the through hole 21a of the support portion 21 is , may be closed on the side of the other end surface 21b in the axial direction.

Also, instead of the distal end portion 50 a of the optical fiber cable 50 , the folded portion of the optical fiber cable 50 may be fixed in the support portion 21 . are connected.

Three members, the optical fiber cable 50 , the supply pipe 24 and the filling hose 30 , which are provided along the outer peripheral surface of the pipe material 10 along the axial direction, are fixed to the pipe material 10 with the fixing tape 14 . A plurality of fixing tapes 14 are provided at predetermined intervals in the axial direction.

Moreover, the holding unit 100 further has a flange 16 for fixing the proximal end portion of the pipe material 10 to the boring hole 2 at the opening end 2 b of the boring hole 2 .

The flange 16 is a plate-like member provided to support the proximal end portion of the pipe material 10 protruding outside the boring hole 2 when the holding unit 100 is inserted into the boring hole 2. 10, an optical fiber cable 50 and a filling hose 30 provided around the pipe material 10 can be inserted through an insertion hole 16a, and an anchor bolt 4 embedded in the ground 1 so as to surround the opening of the boring hole 2 is inserted. and a plurality of bolt holes 16b.

The flange 16 is fixed to the boring hole 2 by tightening the nuts 5 screwed onto the anchor bolts 4. The positions of the insertion holes 16a and the bolt holes 16b formed in the flange 16 are The positions where the anchor bolts 4 are embedded are set in advance so that the axis of the pipe member 10 inserted into the insertion hole 16 a substantially coincides with the axis of the boring hole 2 .

The insertion hole 16a of the flange 16 has an inner diameter that allows the pipe material 10 and the optical fiber cable 50 and the filling hose 30 provided around the pipe material 10 to be inserted with a margin. Therefore, a gap is formed between the inner peripheral surface of the insertion hole 16 a of the flange 16 and the outer peripheral surface of the pipe material 10 , the optical fiber cable 50 and the filling hose 30 . This gap is sealed with a sealing agent such as an epoxy-based adhesive or ultra-rapid cement (not shown).

Further, the flange 16 is provided with a sealing material injection hole (not shown) whose one end opens in the boring hole 2 . In the base end portion fixing step described later, a sealing material 18 such as a urethane material is injected into the vicinity of the flange 16 in the boring hole 2 through the sealing material injection hole, thereby closing the open end 2b of the boring hole 2, The space inside the boring hole 2 is in a state of being shut off from the outside.

The flange 16 does not have to be a single plate-like member, and may be a split flange composed of a plurality of members that partially overlap each other to form the insertion hole 16a. Further, instead of forming the sealing material injection hole in the flange 16, an injection hose for injecting the sealing material 18 may be separately inserted into the insertion hole 16a.

An optical fiber cable 50 is formed by filling a grout 40 (filler) such as cement bentonite through a filling hose 30 into the space in the boring hole 2 blocked by injecting the sealing material 18 into the open end 2b. are embedded in the borehole 2 together with the pipe material 10 and are substantially integrated with the ground 1 . When the grout 40 is filled, the air in the boring hole 2 is discharged out of the boring hole 2 through the communication hole 12 and the internal passage 11 of the pipe member 10 .

2 and 3, a method for installing the fiber optic cable 50 in the borehole 2 as shown in FIG. 1 will now be described.

First, an insertion step is performed for inserting the pipe member 10 to which the optical fiber cable 50 is attached into the boring hole 2 .

In this step, as shown in FIG. 2A, the holding unit 100 having the above configuration is gradually inserted vertically upward into the boring hole 2 . At this point, the expanded portion 22 of the expanded diameter body 20 is not expanded, and the outer diameter of the expanded diameter body 20 is smaller than the inner diameter of the boring hole 2 . The insertion step is completed when the other axial end surface 21b of the support portion 21 of the enlarged diameter body 20 comes into contact with the bottom surface 2a of the boring hole 2. As shown in FIG.

After the insertion step is completed, the tip portion fixing step of fixing the tip portion of the pipe member 10 inserted into the boring hole 2 to the boring hole 2 is performed.

In this step, as shown in FIG. 2(B), the diameter of the expanding member 20 is expanded radially outward so that the portion of the pipe material 10 on which the expanding member 20 is provided is located on the boring hole 2 . fixed against.

Specifically, pressurized water is supplied to the inflatable portion 22 through the supply pipe 24 to inflate the inflatable portion 22 radially outward. The expansion part 22 generates a load that presses the inner wall surface of the boring hole 2 , so that the tip of the pipe material 10 is fixed substantially in the center of the boring hole 2 via the diameter expanding member 20 . In other words, the portion of the holding unit 100 provided with the expanded diameter member 20 cannot move in the radial direction. The portion located at is still in a state in which it is possible to move in the radial direction.

When the distal end fixing step is completed in this manner, the proximal end fixing step of fixing the proximal end of the pipe material 10 to the boring hole 2 at the open end 2b of the boring hole 2 is subsequently performed.

In this step, as shown in FIG. 2(C), the base end portion of the pipe material 10 protruding outside the boring hole 2 is fixed to the boring hole 2 via a flange 16 .

Specifically, first, the pipe member 10 and the optical fiber cable 50 and the filling hose 30 provided around the pipe member 10 are inserted into the insertion hole 16a of the flange 16, and the ground 1 is inserted into the bolt hole 16b of the flange 16. Anchor bolts 4 embedded in are inserted. The supply pipe 24 attached along the pipe material 10 together with the optical fiber cable 50 is cut off near the opening end 2b of the boring hole 2 when the supply of pressurized water to the inflatable portion 22 is completed in the tip fixing step. The other end 24b of the supply pipe 24, which is the cut end, is accommodated in the boring hole 2 without being inserted into the insertion hole 16a.

The flange 16 is fixed to the boring hole 2 by tightening the nut 5 screwed onto the anchor bolt 4 .

By fixing the flange 16 to the boring hole 2, the space between the outer peripheral surface of the pipe material 10 and the inner peripheral surface of the boring hole 2, which is filled with a filler in the filling process described later, is defined by the flange 16. It becomes almost blocked. In other words, the flange 16 functions as a shielding member that prevents the filling material filled in the boring hole 2 from leaking to the outside.

Further, by fixing the flange 16 to the boring hole 2 , the proximal end portion of the pipe material 10 is in a state in which radial movement is restricted at substantially the center of the boring hole 2 . It will be in a fixed state.

When the tip end and the base end of the pipe material 10 are fixed to the boring hole 2 in this way, the optical fiber cable 50 attached to the pipe material 10 along the axial direction and the inside of the boring hole 2 are installed. The distance between the wall surface and , is approximately the same size in the axial direction. That is, the positioning of the optical fiber cable 50 with respect to the boring hole 2 is completed by fixing the distal end portion and the proximal end portion of the pipe material 10 with respect to the boring hole 2 .

In addition, in the base end fixing step, as a preparatory step for the filling step of filling the grout 40 into the boring hole 2, an injection step of injecting the sealing material 18 into the opening end 2b of the boring hole 2 is also performed. The injection process is performed to prevent the grout 40 filled in the boring hole 2 from leaking out from the open end 2b of the boring hole 2 in the filling process described later.

In the injection step, as shown in FIG. 3A, a sealing material 18 such as a urethane material is injected into the boring hole 2 through a sealing material injection hole (not shown) provided in the flange 16 .

Specifically, first, in order to prevent the sealing material 18 from leaking out of the boring hole 2, the inner peripheral surface of the insertion hole 16a of the flange 16, the outer peripheral surface of the pipe material 10, and the optical fiber cable 50 are separated. and the filling hose 30, a super fast hardening cement (quick setting cement) or the like is applied as a sealant. The sealing agent may be applied when the pipe member 10 or the like is inserted into the insertion hole 16a, or may be applied after the pipe member 10 or the like is inserted into the insertion hole 16a. Also, the contact surface between the flange 16 and the ground 1 may be coated with a sealant.

When the applied sealant is solidified, the sealant 18 is injected through the sealant injection hole provided in the flange 16 . After the injection of the predetermined amount of the sealing material 18 is completed, the sealing material injection hole is sealed with a plug material (not shown).

The sealing material 18 injected into the boring hole 2 solidifies so as to close the open end 2b of the boring hole 2. As shown in FIG. As a result, the space in the boring hole 2 is substantially blocked from the outside, that is, even if the boring hole 2 is filled with the grout 40, the grout 40 leaks out from the opening end 2b of the boring hole 2. It will be in a state where it can be suppressed.

Subsequently, when the proximal end portion fixing step including the injection step is completed and the injected sealing material 18 is solidified, that is, when the sealing material 18 injected into the open end 2b is solidified, the pipe material 10 is fixed. When the space between the outer peripheral surface and the inner peripheral surface of the boring hole 2 is cut off from the outside, a filling step of filling the boring hole 2 with the grout 40 is performed.

In this step, as shown in FIG. 3B, grout 40 is injected as a filler into the boring hole 2 through a filling hose 30 .

Specifically, the grout 40 pressure-fed from a force-feeding pump (not shown) passes through the filling hose 30 and is discharged into the boring hole 2 from the discharge port 30a. The grout 40 discharged into the boring hole 2 flows vertically downward due to gravity, and the space inside the boring hole 2 is gradually filled with the grout 40 from the open end 2b side.

Since the opening end 2b side of the boring hole 2 is closed with the sealing material 18 as described above, the grout 40 is prevented from leaking out from the opening end 2b of the boring hole 2. FIG.

Further, as described above, since the pipe member 10 is provided with the communication hole 12 that communicates between the inside and the outside of the pipe member 10, as the grout 40 is filled into the boring hole 2, , the air in the borehole 2 is discharged to the outside of the borehole 2 through the communication hole 12 and the internal passage 11 .

When the grout 40 is further filled into the boring hole 2, the liquid surface of the grout 40 eventually reaches the communication hole 12 as shown in FIG. 3(C).

When the filled grout 40 reaches the communication hole 12 , part of the grout 40 leaks out of the boring hole 2 through the communication hole 12 and the internal passage 11 . When it is confirmed that the grout 40 has leaked through the pipe material 10 in this way, the pumping of the grout 40 through the filling hose 30 is stopped, and the filling process is completed.

When the distal end fixing process and the proximal end fixing process are completed as described above, the positioning of the optical fiber cable 50 with respect to the borehole 2 is completed, and the position of the optical fiber cable 50 is maintained even during the filling process. be done. In particular, the position of the fiber optic cable 50 relative to the borehole 2 can be adjusted by fixing both the distal and proximal ends of the pipe material 10 to the borehole 2, rather than either the distal or proximal ends thereof. is reliably held at a predetermined position without being displaced under the influence of the pumping of the grout 40 .

Therefore, when the grout 40 filled in the filling process is solidified, as shown in FIG. 1, the distance between the optical fiber cable 50 and the inner wall surface of the boring hole 2 does not fluctuate in the axial direction, and the distance between the optical fiber cable 50 and the inner wall surface is substantially the same. It will be embedded in the boring hole 2 in a state of being flat.

The strain in the ground surrounding the boring hole 2 in which the optical fiber cable 50 is embedded is transmitted to the optical fiber cable 50 through the solidified grout 40 from the inner wall surface of the boring hole 2 without causing variations. be. Therefore, by measuring the strain of the optical fiber cable 50 installed in the borehole 2 as described above, the position and magnitude of the strain in the ground can be accurately measured.

In addition, the strength and rigidity of the grout 40 interposed between the ground 1 and the optical fiber cable 50 are about the same as the strength and rigidity of the ground 1, considering the transmission of distortion in the ground to the optical fiber cable 50. or adjusted to be less.

According to the above embodiment, the following effects are obtained.

According to the linear body installation method of the present embodiment, in the tip portion fixing step, the tip portion of the pipe member 10 to which the optical fiber cable 50 is attached along the axial direction is fixed to the boring hole 2, and the base is fixed. In the end fixing step, the base end of the pipe member 10 is fixed to the boring hole 2 at the open end 2b of the boring hole 2. As shown in FIG.

By fixing the distal end portion and the proximal end portion of the pipe material 10 to the boring hole 2 in this way, the optical fiber cable 50 attached to the pipe material 10 along the axial direction and the inner portion of the boring hole 2 are installed. The distance between the wall surface and , is approximately the same size in the axial direction. That is, by fixing the distal end portion and the proximal end portion of the pipe material 10 to the boring hole 2, the position of the optical fiber cable 50 relative to the boring hole 2 is reliably held at a predetermined position.

Therefore, according to the linear body installation method described above, it is possible to efficiently position the optical fiber cable 50 in the boring hole 2 .

By burying the optical fiber cable 50 in the boring hole 2 in a state that the distance between the inner wall surface of the boring hole 2 and the inner wall surface of the boring hole 2 is substantially the same in the axial direction, The strain is transmitted from the inner wall surface of the boring hole 2 through the solidified grout 40 to the optical fiber cable 50 without causing variations. Therefore, by measuring the strain of the optical fiber cable 50 installed in the borehole 2, the position and magnitude of the strain in the ground can be accurately measured.

The following modifications are also within the scope of the present invention, and it is possible to combine the configurations shown in the modifications with the configurations described in the above embodiments, or to combine the configurations described in different modifications below. is also possible.

In the above embodiment, the supply pipe 24 and the filling hose 30 are provided along the axial direction on the outer peripheral surface of the pipe member 10 together with the optical fiber cable 50 . Alternatively, the supply pipe 24 and filling hose 30 may be provided through the internal passage 11 of the pipe material 10, as in the variant shown in FIG.

Specifically, one end of the supply pipe 24 connected to the space between the support portion 21 and the expansion portion 22 is pulled out of the pipe material 10 through the communication hole 12, and the filling hose 30 is a discharge port. 30 a is drawn out of the pipe member 10 through the communication hole 12 . The discharge port 30a is fixed to the pipe material 10 by the fixing tape 14 so as to be positioned below the communication hole 12 in the vertical direction.

In this modification, since only the pipe material 10 and the optical fiber cable 50 are substantially inserted into the insertion hole 16a of the flange 16, the inner peripheral surface of the insertion hole 16a and the pipe material 10, etc. The gap between them can be easily sealed with a sealant.

Further, in the above embodiment, the hollow pipe member 10 is used as the bar member 10 to which the optical fiber cable 50 is attached. Alternatively, bar 10 may be a solid bar-like member. In this case, an exhaust pipe is separately provided along the bar 10 for discharging the air inside the borehole 2 to the outside during the filling process.

Further, in the above-described embodiment, the diameter-expanding body 20 expands radially outward according to the pressure of the supplied fluid. Alternatively, the diameter expander 20 may be of any type as long as it has a structure that allows the diameter to be expanded when insertion into the borehole 2 is completed. It may be one that mechanically expands the diameter by coming into contact with the bottom surface 2a, or one that is provided with a gas generator that generates gas for inflating the inflatable portion 22 in response to contact with the bottom surface 2a or switch operation. .

Further, in the above-described embodiment, the case where the linear body is the optical fiber cable 50 has been described, but the linear body installed in the borehole 2 is not limited to this, and the state of the ground 1 can be detected. Any linear body may be used, for example, a linear body in which a plurality of sensors capable of detecting pressure and temperature are connected at regular intervals, or a metal wire such as a thermocouple may be used. Further, the state of the ground 1 to be detected is not limited to underground distortion, and may be underground temperature or pressure.

Further, in the above embodiment, the case where the boring hole 2 is excavated vertically upward has been described, but the boring hole 2 may be excavated vertically downward or horizontally or horizontally. may be excavated upward or downward by a predetermined angle from the Even when the boring hole 2 is drilled in this manner, the positioning of the optical fiber cable 50 in the boring hole 2 can be efficiently performed by the method described above.

Although the embodiments of the present invention have been described above, the above embodiments merely show a part of application examples of the present invention, and the technical scope of the present invention is not limited to the specific configurations of the above embodiments. Absent.

1... Ground 2... Boring hole (hole)
2a... Bottom surface 2b... Open end 10... Bar material (pipe material)
DESCRIPTION OF SYMBOLS 11... Internal passage 12... Communication hole 16... Flange 18... Sealing material 20... Diameter expansion body 30... Filling hose 40... Grout (filling material)
50 Optical fiber cable (linear body)
60... Measuring device 100... Holding unit

Claims (4)

A linear body installation method for installing a linear body in a hole formed in the ground,
an inserting step of inserting into the hole a rod having a diameter-expandable diameter-expandable body provided at a distal end portion on the radially outer side of the hole and having the linear body attached to the outer peripheral surface along the axial direction;
a tip portion fixing step of expanding the diameter-expanding body radially outward and fixing the tip portion of the bar to the hole;
a base end portion fixing step of fixing the base end portion of the bar to the hole at the opening end of the hole;
Linear body installation method. The rod material is a hollow pipe material and has a communication hole that communicates between the inside and the outside.
The linear body installation method according to claim 1 . Further comprising a filling step of filling a filler into the hole,
In the filling step, the filling material is filled between the outer peripheral surface of the bar and the inner wall surface of the hole, and the air in the hole can be discharged out of the hole through the communication hole.
The linear body installation method according to claim 2. In the base end fixing step, a sealing material is injected between the outer peripheral surface of the bar and the inner wall surface of the hole at the open end of the hole.
The method for installing a linear body according to any one of claims 1 to 3.

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