JP2006242920A - Anchor for sensing optical cable and method of laying the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve workability for adjusting the tension of a cable, and to easily cope with the tilt of the cable. <P>SOLUTION: An anchor 1 has a clamper 5, consisting of a pair of waveform members 3, 4 with irregular waveform surfaces 3a, 4a mating with each other. The clamper 5 is fixed to a holding member 7 with a clamper-gripping bolt 11 and clamps and fixes the sensing optical cable 2 to the waveform members 3, 4. The holding member 7 is mounted on a mount 8, and the tension of the cable can be adjusted by a simple operation of an adjusting bolt 9, thereby providing good workability. When it is necessary to detach the cable 2 from the anchor 1 or to loosen the cable 2, it can be performed simply by loosening the gripping bolt 11. Consequently, the relaying of the cable or its tension readjustment can easily be performed without damaging the anchor, which enables reuse of the anchor. When the cable 2 is tilted between the adjacent anchors 1, the angle of the cable can naturally be changed along the surfaces of the guides 3a, 4a. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  This invention uses optical fiber to displace ground, bedrock, structures, etc., for example, aging tunnels or fine subsidence of buildings that are at risk of peeling or collapsing walls, or a small amount of these tunnels or structures. The present invention relates to an optical fiber sensor capable of detecting a simple inclination and detecting the possibility of landslide, landslide, and collapse in advance, and is particularly configured to detect Brillouin backscattered light of an optical fiber with a measuring instrument B-OTDR. The present invention relates to a sensing optical cable fixture suitable for laying a sensing optical fiber used in a slope collapse monitoring system, and a sensing optical cable fixture laying method.

  As described above, for example, as an example of a method of supporting and fixing a sensing optical fiber to a slope in a slope collapse monitoring system by B-OTDR using Brillouin backscattered light of an optical fiber, the sensing optical fiber is long on a slope, a wall surface, etc. A method of applying a certain tension while fixing at a plurality of locations in the vertical direction is employed.

  As a result, a change in tension applied to the sensing optical fiber is generated due to slope distortion, settling, inclination, etc., and the resulting Brillouin backscattered light is added to the sensing optical fiber by monitoring using the measuring instrument B-OTDR. Observe the distortion situation, for example, the distortion change due to the change of the installation surface.

  As a structure for fixing a plurality of locations of the sensing optical fiber to a measurement target such as a slope ground, there is known a fixing structure for fixing the sensing optical fiber to a slope by a plastic optical fiber fixing jig used in Patent Document 1, for example. It has been.

  This optical fiber fixing jig is composed of a split sleeve that can be gripped with each other, and the optical fiber for sensing is gripped and fixed so that it does not move in either direction by passing through the optical fiber for sensing. It has a structure to do.

The sensing optical fiber laying operation is performed, for example, after the operator manually adjusts the tension using a three-point supported tension meter to adjust the tension tension, and then adjusts the sensing light. The fiber is sandwiched between the fixing jigs and fixed at a predetermined position on the rock. At that time, a fixing jig is inserted into the jig receiving hole of the jig holder having an L-shaped cross section fixed to the rock, and a split-type nut is screwed to the outer periphery of the fixing jig on both sides of the jig holder. And tighten the nut to fix the fixing jig to the jig holder. After completing all the fixing operations for the entire length of the sensing optical fiber, the tension of the entire sensing optical fiber is monitored using a B-OTDR (Brillouin-Optical Time Domain Reflectometer) to reconfirm the installation status. I am doing so.
JP 2002-48675 A JP 2000-9439 A JP 2001-281462 A

  By the way, there are many places where the construction environment of the sensing optical fiber is usually poor, such as the inner surface of the tunnel, the wall surface of the building, and the slope of the cliff, and accurate tension adjustment of the sensing optical fiber may not be easy. There are many.

The fixing jig of Patent Document 1 has a problem that workability of tension adjustment is not always good. That is, B-OTDR measurement is performed after laying work. As a result, when a section where the optical fiber for sensing is not tight is found, the position of the fixing jig with respect to the jig holder is adjusted to adjust the tension. However, in order to obtain a desired tension, the two nuts screwed to the fixing jig on both sides of the jig holder must be rotated many times with a tool such as a spanner. For this reason, it takes time to adjust the tension.
There is also a problem in re-construction. In other words, if the desired tension cannot be obtained even after the above tension adjustment work, or once it has been applied, it may be necessary to re-install it. At that time, the fixing jig is disassembled (opened) and used for sensing. It is necessary to take out the optical fiber and reattach it after adjusting the tension again using a tensiometer. In that case, once the split-shaped sleeve is integrated once, the fixing jig is firmly coupled. Therefore, the disassembly requires a special tool and is complicated. Further, the gripping protrusion of the fixing jig is broken at the time of dismantling, and cannot be reused.
There is also a problem that the angle adjustment in the height direction is complicated. That is, for example, when laying on a rock slope, the rock slope usually has irregularities, but in order to avoid the irregularities, the base on which the L-shaped jig holder is placed is raised, or the pillars are erected, A method of attaching the jig support is taken. In this case, an inclination may occur between one of the adjacent fixing points of the sensing optical cable and the other fixing point, and it is necessary to attach an angle adjusting mechanism to the jig holder.

  The present invention was made in order to eliminate the above-mentioned conventional drawbacks, the workability of tension adjustment of the optical cable for sensing is good, the re-installation is easy and the fixture can be reused, and the height direction It is an object of the present invention to provide a sensing optical cable fixture that allows easy angle adjustment and a method of constructing the sensing optical cable.

The invention according to claim 1 that solves the above-mentioned problem is to fix a plurality of locations in the length direction of the sensing optical cable to the measurement object, detect a displacement generated in the measurement object as distortion of the sensing optical cable, and perform the measurement. A sensing optical cable fixture used in a displacement detection system for detecting displacement generated in an object,
A clamper made up of a pair of corrugated members having corrugated concave and convex surfaces fitted together, and a holding mechanism for holding the clamper holding the sensing optical cable between the corrugated concave and convex surfaces so as to be movable and adjustable in the cable length direction. It is characterized by that.

  According to a second aspect of the present invention, the holding mechanism of the optical fiber cable for sensing according to the first aspect is a holding member that directly holds the clamper and a member that is fixed to the measurement target, and the holding member can be moved in the cable length direction. And an adjusting bolt for adjusting the position of the holding member in the cable length direction with respect to the mounting base.

  According to a third aspect of the present invention, the holding member in the fixture of the optical fiber for sensing according to the second aspect includes a clamper receiving groove for slidably receiving the clamper in the cable length direction, and the clamper in the clamper receiving groove faces the groove bottom. And a clamper holding bolt for pressing and fixing.

  According to a fourth aspect of the present invention, there is provided the sensing optical cable fixture according to the second aspect, further comprising a fixing bracket for fixing the mounting base to the support column set up on the measuring object.

  According to a fifth aspect of the present invention, in the clamper in the optical fiber cable for sensing according to the first aspect, one corrugated member has a single wave shape, and the other corrugated member has a wave shape to be fitted thereto. And

  According to a sixth aspect of the present invention, in the fixture for an optical cable for sensing according to the first or fifth aspect, a guide portion is formed in which the opposing surfaces of the corrugated members are widened in the vicinity of at least one end of the pair of corrugated members of the clamper. It is characterized by that.

  According to a seventh aspect of the present invention, in the fixture for a sensing optical cable according to the first, fifth, or sixth aspect, a guide pin that regulates a position in the width direction of the sensing optical cable is provided on the corrugated uneven surface of the corrugated member of the clamper. To do.

  According to an eighth aspect of the present invention, in the optical fiber cable for sensing according to the first aspect, the holding member and the mounting base have a C-shaped cross-sectional shape back to back, and the clamper is located on one flange portion side of the C-shaped cross section of the holding member. One end of the holding member at the back of the cable in the cable length direction is fixed by being pressed against the groove on the flange side by screwing a clamper grip bolt that is slidably fitted into the groove and screwed to the other flange side. Protrusions that extend at right angles from the opening opened on the back of the mounting base to the inside of the C-shaped cross section of the mounting base, and bend at right angles to one end of the mounting base in the cable length direction. Provided with a projecting piece having a shape facing the projecting piece of the holding member, the tip end side of the adjusting bolt inserted from the hole drilled in one projecting piece is screwed into a nut fixed to the other projecting piece, and the retaining member and the mounting base The other end of each back of the Characterized in that it is fixed Bull possible relative position adjustment of the length.

  According to a ninth aspect of the present invention, there is provided the optical fiber cable for sensing according to the eighth aspect, wherein the holding member and the mounting base are used as means for fixing the other end side of each back portion of the holding member and the mounting base so that the relative position in the cable length direction can be adjusted. An elongated hole is formed in one of the back portions, a nut is fixed to the other, and a tip end portion of a slide fixing bolt passed through the elongated hole is screwed into the nut and tightened.

The tenth aspect of the present invention is to fix a plurality of locations in the length direction of a sensing optical cable to a measurement object, detect a displacement generated in the measurement object as distortion of the sensing optical cable, and generate a displacement in the measurement object. Laying the sensing optical cable in a displacement detection system for detecting the sensing optical cable,
At least one mounting base is directly or indirectly fixed to a measurement object, a sensing optical cable is sandwiched between a pair of corrugated members having corrugated concave and convex surfaces that fit together, and the clamper is directly attached to the mounting base. Or indirectly, it is movably engaged in the cable length direction, and the tension of the sensing optical cable is adjusted by moving and adjusting the clamper in the cable length direction with respect to the mounting base.

According to the eleventh aspect of the present invention, a plurality of locations in the length direction of the sensing optical cable are fixed to the measurement target, and a displacement generated in the measurement target is detected as a distortion of the sensing optical cable. Laying the sensing optical cable in a displacement detection system for detecting the sensing optical cable,
At least one mounting base is directly or indirectly fixed to the measurement target, and the sensing optical cable is sandwiched between a pair of corrugated members having corrugated concave and convex surfaces that fit together, and the clamper is held by a holding member. The holding member is engaged with the mounting base so as to be movable in the cable length direction, and an adjustment bolt in the cable length direction for engaging the holding member and the mounting base is provided to adjust the tension of the optical cable for sensing. In this case, the position in the cable length direction with respect to the mounting base of the holding member is adjusted by the adjusting bolt.

According to the present invention, the sensing optical cable is sandwiched between a pair of corrugated members, so that the cable can be easily attached and detached, for example, by pressing one corrugated member against the other corrugated member at the tip of the clamper grip bolt. Can be gripped firmly. Therefore, when re-installing the cable or re-adjusting the tension, the cable can be easily removed from the fixture, or the cable can be easily released to loosen the cable. Construction or tension readjustment is easy.
In addition, as described above, the cable can be removed or loosened by simply loosening the clamper gripping bolt, so that the fixture is not damaged and the fixture can be reused.

In addition, when there is an inclination between one of the two adjacent fixing points of the cable and the other fixing point, a guide portion is formed in which the opposing surfaces of the corrugated members are curved forward to form a curved surface. Thus, the angle of the cable can be changed naturally along the guide portion surface, and therefore, it is not necessary to provide a special mechanism for adjusting the angle.
In addition, the cable tension can be adjusted by moving the clamper in the cable length direction by a simple operation such as turning an adjustment bolt. Is good.
In addition, since the cable can be gripped by the pair of corrugated members of the clamper by a simple operation such as turning the clamper gripping bolt, the workability of tension adjustment is also good in this respect.

  Hereinafter, a sensing optical cable fixture and a sensing optical cable laying method embodying the present invention will be described with reference to the drawings.

The sensing optical cable fixture of the present invention fixes a plurality of locations in the length direction of the sensing optical cable to a measurement object such as a rock, and detects a displacement generated in the measurement object as distortion of the sensing optical cable. It is a fixture of the optical cable for sensing used for the displacement detection system which detects the displacement which arose in the said measuring object.
As a measuring device for detecting distortion of an optical cable for sensing, generally, a measuring instrument B-OTDR that uses the fact that the wavelength shift amount of Brillouin scattered light changes due to distortion applied to an optical fiber is used. In a sensor based on B-OTDR, a sensing optical fiber cable is laid with a certain tension applied as a general method. A change in the tension of the optical cable for sensing occurs due to a change in the distance between the two points, and the amount of movement (displacement) of the distance between the two points is observed by monitoring the change amount using B-OTDR. In such a displacement detection system, it is a fixture used to fix the sensing optical cable to the measurement object.

1 is a front view of a sensing optical cable fixture 1 according to an embodiment of the present invention, FIG. 2 is a plan view of FIG. 1, FIG. 3 is a right side view of FIG. 1, and FIG. FIG. 5 and FIG. 5 are BB cross-sectional views of FIG.
The sensing optical cable fixture 1 fixes a plurality of locations in the length direction of the sensing optical cable to a measurement target such as a rock, and detects displacement generated in the measurement target as distortion of the sensing optical cable. It is a fixture of the optical cable for sensing used for the displacement detection system which detects the displacement which arose in the said measuring object.
The sensing optical cable fixture 1 includes a clamper 5 composed of a pair of corrugated members 3 and 4 having corrugated uneven surfaces 3a and 4a fitted to each other, and an optical cable for sensing (in some cases) between the corrugated uneven surfaces 3a and 4a. And a holding mechanism 6 that holds the clamper 5 holding the pin 2 so as to be movable and adjustable in the cable length direction (left and right direction in FIG. 1).

As shown in FIG. 6, a guide pin 14 that regulates the position in the width direction of the cable 2 is provided on the corrugated uneven surface 4 a of the corrugated member 4 on the lower side of the clamper 5. The corrugated member 3 on the upper side is provided with a pin hole for relative positioning into which the guide pin 14 is fitted. On the lower surface of the corrugated member 4 on the lower side, a protrusion 4c having a rectangular cross section for positioning the clamper 5 with respect to the holding member 7 in the cable length direction is provided.
Further, guide portions 3b and 4b that are curved forwardly are formed on the opposing surfaces of the corrugated members 3 and 4 on one side in the cable length direction (right side in FIGS. 1 and 6B). This is because the cable 2 can naturally change the angle along the surfaces of the guide portions 3b and 4b.

  The holding mechanism 6 includes a holding member 7 that directly holds the clamper 5, a member that is fixed to a measurement target and that engages the holding member 7 so as to be movable in the cable length direction, and the holding member An adjustment bolt 9 for adjusting the position in the cable length direction with respect to the mounting base 8 is provided.

Each of the holding member 7 and the mounting base 8 has back portions 7a and 8a, flange portions 7b and 8b bent at right and left at the upper and lower sides thereof, and lip portions 7c and 8c bent inward from the front ends thereof. It has a C-shaped cross-sectional shape and is back-to-back where the back portions 7a and 8a contact each other.
A groove 7d in the lower flange portion of the holding member 7 having a C-shaped cross-section is a clamper accommodating groove 7d that accommodates the clamper 5 so as to be slidable in the cable length direction. The nuts 10 are welded and fixed to two hole portions provided in the upper flange portion 7b on the opposite side of the clamper housing groove 7d, and the clamper grip bolts 11 are screwed to the nuts 10, respectively. A pressing pad 12 is fixed to the tip of the clamper holding bolt 11. Reference numeral 13 denotes a loosening prevention nut.

Further, a protruding piece 7e is provided on one end of the back portion 7a of the holding member 7 in the cable length direction so as to extend at right angles from the opening 8d opened in the back portion 8a of the mounting base 8 into the C-shaped cross section of the mounting base 8. Yes. Further, a protruding piece 8e having a shape that is bent at a right angle and faces the protruding piece 7e of the holding member 7 is provided on the same one end side of the back portion 8a of the mounting base 8 in the cable length direction. Then, the adjusting bolt 9 is inserted through a hole 8f formed in the protruding piece 8e on the mounting base 8 side, and screwed into a nut 15 that is welded and fixed with its tip side aligned with the hole 7f of the protruding piece 7e on the holding member 7 side. I am letting.
Further, on the other end side (right side in FIG. 1) of each of the back portions 7a and 8a of the holding member 7 and the mounting base 8, a long hole 8g is opened on the mounting base 8 side, a round hole 7g is opened on the holding member 7 side, and a nut 17 is formed. The welding is fixed. Then, the slide fixing bolt 16 passed through the long hole 8g of the back portion 8a of the mounting base 8 is screwed into the nut 17 on the back portion 7a side of the holding member 7 and screwed to fix the back portions 7a and 8a.

  A rectangular hole 7h is formed in the lower flange portion 7b of the holding member 7, and the protrusion 4c on the lower surface of the lower corrugated member 4 is fitted to the clamp member 5 in the cable length direction with respect to the holding member 7. Positioning is performed.

  Said fixing tool 1 is fixed to the support | pillar 22 fixed to measuring objects, such as a rock mass. In the illustrated example, a hat-shaped fixing bracket 20 is fixed to the back portion 8 a of the mounting base 8 of the fixture 1 with, for example, four bolts 21, and the fixing bracket 20 is fixed with bolts 23 and nuts 24 penetrating the column 22. The column 22 is fixed. The bolt 21 is screwed into a nut 25 that is welded and fixed to a hole formed in the back portion 8 a of the mounting base 8, and fixes the mounting base 8 to the fixing bracket 20.

When laying the sensing optical cable 2 using the fixture 1 described above, the following steps (1) to (4) are performed.
(1) The holding member 7, the mounting base 8, and the fixing bracket 20 are attached.
First, the clamper grip bolts 11 are screwed into the two nuts 10 of the upper flange portion 7b of the holding member 7, respectively. The thrust pad 12 is fitted into the tip of the clamper grip bolt 11.
Next, on one end side of the holding member 7, the protruding piece 7 e is inserted into the C-shaped cross section of the mounting base 8 from the opening 8 d of the mounting base 8, and the adjustment bolt 9 is inserted and held from the protruding piece 8 e side of the mounting base 8. The nut 7 of the protruding piece 7e of the member 7 is screwed. Further, on the other end side of the holding member 7, the slide fixing bolt 16 is screwed into the nut 17 of the back portion 7 a of the holding member 7 through the long hole 8 g of the back portion 8 a of the mounting base 8.
Next, the fixing bracket 20 is fixed to the mounting base 8 with four bolts 21.

Next, the fixture 1 to which the fixing bracket 20 is integrally attached is fixed to a column 22 fixed to a measurement object 30 such as a rock mass as shown in FIGS. Reference numeral 22 a denotes a base plate of the support 2. In this case, the fixing bracket 20 is fitted onto the support column 22 from above, the entire fixture 1 is lowered to the specified height of the support column 22, the holes are drilled on the support column 22 in accordance with the holes formed on both side surfaces of the fixing bracket 20. To make a hole. Next, the nut 24 is screwed into the bolt 23 passed through the hole, and is fastened and fixed.
Note that the fixing bracket 20 can be firmly fixed by fixing the fixing bracket 20 with the bolt 23 penetrating the support column 22. However, when the bolt 23 passing through the support column 2 is not used, the fixing bracket 20 is attached to the mounting base 8 with the bolt 21. At the time of fixing, the bolt 21 is loosened and the fixing bracket 20 is temporarily fixed to the mounting base 8, the fixing bracket 20 is fitted onto the column 22 from above, and the entire fixture 1 is set to the specified height of the column 22. After the lowering, the bolt 21 is completely tightened with a hexagon wrench to fix the fixture 1 to the column 22.

When the fixing tool 1 is fixed to the support column 2 in the above operation, particularly in a place where there is an inclination between adjacent fixing points of the cable 2, the direction of the clamper 5 of the adjacent fixing tool 1 is changed as shown in FIGS. Make them face each other. That is, the two adjacent fixtures 1 are arranged so that the guide portions 3b and 4b of the corrugated members 3 and 4 of the clamper 5 face each other. Therefore, in this embodiment, as shown in FIGS. 7 and 8, one (left side) fixing tool 1 is fixed to the front surface of the column 2, and the other (right side) fixing device 1 is fixed to the back surface of the column 22. ing.
7 shows the cable 22 with no inclination between adjacent fixing points, but in FIG. 9, the right-side fixing tool 1 is fixed below the support 22 from the left-hand side. There is an inclination between the fixed points.

(2) Fix the cable 2 to the clamper 5.
First, as shown in FIG. 6B, the cable 2 is arranged along the guide pins 14 on the corrugated member 4 on the lower side of the clamper 5.
Next, as shown in FIG. 6A, the upper corrugated member 3 of the clamper 5 is put on the lower corrugated member 4 so that the pin hole and the guide pin 14 are put together to sandwich the cable 2.
Next, the clamper 5 (the corrugated members 3 and 4) is inserted into the clamper receiving groove 7d of the holding member 7 from the side surface. At that time, the protrusion 4c on the lower surface of the lower corrugated member 4 is fitted into a square hole 7h provided in the holding member 7, and the clamper 5 is positioned in the cable length direction with respect to the holding member 7.
Next, the clamper grip bolt 11 on the upper portion of the holding member 7 is tightened using a torque wrench so that pressure is evenly applied to the clamper 5.

  (3) The steps (1) and (2) described above are repeated for each fixing point of the cable, and each fixing point of the cable 2 is fixed to each fixing tool 1.

(4) A tension is applied between the fixtures 1 at adjacent fixing points.
By rotating the adjustment bolt 9 of the mounting base 8 with a hexagon wrench and moving the holding member 7 left and right (in the cable length direction), the tension to be applied to the cable is adjusted to a specified value.
In this case, if the looseness of the cable 2 between the fixtures 1 is large, the clamper holding bolt 11 of the clamper 5 is once loosened to release the cable fixation, and then the cable 2 is pulled to some extent and then the tension is adjusted again. The applied tension is confirmed by a tension meter such as a three-point support type.
After adjusting the cable tension to the specified tension as described above, the slide fixing bolt 16 is turned to fix the holding member 7 so as not to move relative to the mounting base 8 in order to maintain the tension.
Thereafter, as shown by a two-dot chain line in FIG.

As described above, in the fixture 1 of the present invention, the cable 2 can be gripped by the clamper 5 by a simple operation of turning the clamper gripping bolt 11. Therefore, in (4) of the cable laying operation described above, even when the cable 2 is loosely loosened between the fixtures 1 and it is necessary to release the cable fixing once for the tension readjustment, the cable fixing is easily released. And tension readjustment is easy. The same applies to the case where re-construction such as readjustment of cable tension is necessary after cable laying is completed once, and re-construction is easy.
Further, since the cable 2 can be removed or loosened by simply loosening the clamper gripping bolt 11 as described above, the fixture 1 is not damaged, and the fixture 1 can be reused.

  Further, when there is an inclination between one of the two adjacent fixing points of the cable 2 and the other fixing point as shown in FIG. 9, the clamper 5 of the adjacent fixing tool 1 as shown in the example of the drawing. The cable 2 can naturally change the angle along the guide part surface 3b or 4b by making the directions of the opposite and the guide parts 3b and 4b of the corrugated members 3 and 4 of the clamper 5 face each other. Therefore, it is not necessary to provide a special angle adjusting mechanism.

In addition, when adjusting the tension, the tension adjustment of the cable 2 can be performed by moving the clamper 5 in the cable length direction by a simple operation of turning the adjustment bolt 9, so that the tension adjustment is extremely easy. The workability of tension adjustment is good.
In addition, the cable 2 can be gripped by the pair of corrugated members 3 and 4 of the clamper 5 by a simple operation of turning the clamper gripping bolt 11, so that the workability of tension adjustment is also good in this respect.

  In the above-described embodiment, the fixing device 1 is attached to the support column 22, but as schematically shown in FIGS. 10 (a) and 10 (b), it may be attached to the anchor 31 driven into the measuring object 30 such as a rock. it can. In the illustrated example, both sides of the horizontal portion 32a of the L-shaped gantry 32 are fixed to two anchors 31 with nuts 33, and the fixture 1 is fixed to the vertical portion 32b with bolts 34. The fixing tool 1 in FIG. 10 is the same as that described with reference to FIGS. 1 to 9, and details are omitted, but the portion of the mounting base 8 of the fixing tool 1 is fixed to the vertical portion 32 b of the gantry 32 with four bolts 34. Good. The horizontal portion 32a and the vertical portion 32b of the gantry 32 indicate relative directions when the anchor 31 is vertical.

In addition, although the clamper 5 of the fixture 1 of the embodiment is provided with the guide portions 3b and 4b only on one side of the corrugated members 3 and 4 in the cable length direction, it can naturally be provided on both sides. It is good to provide the guide parts 3b and 4b on one side or both sides according to the situation where an inclination arises between the adjacent fixing points of a cable. Moreover, when there is no inclination, the guide parts 3b and 4b do not need to be provided.
In addition, the guide portion may be configured such that one of the upper and lower corrugated members 3 and 4 on the side where the inclined cable does not contact is a flat surface and only the other corrugated member on the side where the cable contacts is a curved surface.

Although the corrugated uneven surfaces 3a and 4a of the corrugated members 3 and 4 of the clamper 5 of the embodiment are one mountain (the corrugated member 3 side is one mountain), the number of the mountains is arbitrary and may be two or more.
Moreover, the shape of the holding member 7 and the mounting base 8 is not limited to the shape of the embodiment, and various design changes can be made.
Further, the structure in which the holding member 7 is engaged with the mounting base 8 so as to be movable in the cable length direction is not limited to the structure of the embodiment, and various design changes can be made.
Further, the structure in which the clamper 5 is engaged with the holding member 7 so as to be movable in the cable length direction is not limited to the clamper housing groove 7d, and various design changes can be made.
Further, the structure for holding the clamper 5 with the holding member 7 is not limited to the structure using the clamper receiving groove 7d and the clamper holding bolt 11, and various design changes can be made.
Further, when the cable 2 is clamped by the corrugated members 3 and 4 of the clamper 5, the means for regulating the position in the width direction of the cable 2 is not limited to the guide pin, and a cable housing groove may be formed in the corrugated member. Other means can be employed.
Further, the mechanism for moving and adjusting the holding member 7 with respect to the mounting base 8 in the cable length direction is not limited to the one using the adjusting bolt 9 engaged between the projecting pieces 7a and 8a as in the embodiment, and various designs are possible. It can be changed.
In the above-mentioned embodiment, the example of detecting the displacement of the rock mass has been described. However, the measurement object is arbitrary, and the displacement of the ground, the structure, etc., for example, an aged tunnel or a building having a risk of peeling or collapse of the wall surface. It can be applied to the detection of various displacements such as fine subsidence or slight inclination of these tunnels and buildings.

It is a front view of the fixture of the optical cable for sensing of one Example of this invention. It is a top view of FIG. It is a right view of FIG. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. Only the clamper in the said fixture is shown, (A) is a front view, (B) is an oblique view of the lower corrugated member. It is a front view which shows an example of the state which installed the optical cable for sensing on the bedrock etc. using the said fixing tool, and showed two adjacent fixing points. FIG. 8 is a plan view of FIG. 7. It is the front view which showed the case where the optical cable for sensing in FIG. It is a figure which shows the other example of a means to fix a fixing tool to a bedrock etc., (a) is a front view, (b) is a right view.

Explanation of symbols

1 Fixing device (fixing device for sensing optical cable)
2 Sensing optical cable 3, 4 Corrugated member 3a, 4a Corrugated uneven surface 3b, 4b Guide portion 4c Projection 5 Clamper 6 Holding mechanism 7 Holding member 8 Mounting base 7a, 8a Back portion 7b, 8b Flange portion 7c, 8c Lip portion 7d Clamper Housing groove 8d Opening 7e, 8e Protruding piece 7f, 8f Hole 8g Long hole 7h Square hole 9 Adjustment bolt 10 Nut 11 Clamper gripping bolt 12 Thrust pad 13 Loosening prevention nut 15 Nut 16 Slide fixing bolt 17 Nut 20 Fixing bracket 21 Bolt 22 Post 23 Bolt 24 Nut 25 Nut 26 Cover 30 Object to be measured 31 such as bedrock Anchor 32 Mounting base 33 Nut 34 Bolt

Claims (11)

A displacement detection system for fixing a plurality of sensing optical cables in a length direction to a measurement target, detecting displacement generated in the measurement target as distortion of the sensing optical cable, and detecting the displacement generated in the measurement target. A sensing optical cable fixture to be used,
A clamper made up of a pair of corrugated members having corrugated concave and convex surfaces fitted together, and a holding mechanism for holding the clamper holding the sensing optical cable between the corrugated concave and convex surfaces so as to be movable and adjustable in the cable length direction. An optical cable fixture for sensing.   The holding mechanism includes: a holding member that directly holds the clamper; a mounting member that is a member fixed to a measurement target and is movably engaged with the holding member in a cable length direction; and the mounting of the holding member The fixture for an optical cable for sensing according to claim 1, further comprising an adjustment bolt that adjusts a position in a cable length direction with respect to the base.   The holding member includes a clamper receiving groove for storing the clamper so as to be slidable in the cable length direction, and a clamper holding bolt for pressing and fixing the clamper in the clamper receiving groove toward the groove bottom. The fixture for an optical cable for sensing according to claim 2.   The fixture for an optical cable for sensing according to claim 2, further comprising a fixing bracket for fixing the mounting base to a support column placed on a measurement object.   2. The optical fiber cable for sensing according to claim 1, wherein one of the corrugated members has a corrugated shape, and the other corrugated member has a corrugated shape fitted to the clamper.   6. The optical fiber cable for sensing according to claim 1 or 5, wherein a guide portion is formed in the vicinity of at least one end portion of the pair of corrugated members of the clamper so that the opposing surfaces of the corrugated members are curved forward. Ingredients.   7. The sensing optical cable fixture according to claim 1, wherein a guide pin for regulating a position in the width direction of the sensing optical cable is provided on the corrugated surface of the corrugated member of the clamper.   The holding member and the mounting base have a C-shaped cross-sectional shape back to back, and the clamper is slidably fitted in a groove portion on one flange portion side of the C-shaped cross section of the holding member and screwed on the other flange portion side. By screwing the clamper clamp bolts together, it is pressed and fixed to the groove on the flange side, and the C-shape of the mounting base from the opening on the back of the mounting base at one end in the cable length direction of the back of the holding member Protrusions extending at right angles inside the cross section are provided, and at one end in the cable length direction on the back of the mounting base, a protrusion having a shape that is bent at right angles and faces the protrusion of the holding member is provided. Adjust the relative position in the cable length direction of the holding member and the other end of each back of the mounting base by screwing the tip of the adjustment bolt inserted through the hole in the protrusion into the nut fixed to the other protrusion. Claim characterized by being fixed to First fastener of the sensing optical cable according.   As a means to fix the other end of each back part of the holding member and the mounting base so that the relative position in the cable length direction can be adjusted, a long hole is made in one of the back parts of the holding member and the mounting base, and a nut is fixed to the other side. 9. The optical fiber cable for sensing according to claim 8, wherein a distal end portion of a slide fixing bolt passed through the elongated hole is screwed into the nut and tightened. In a displacement detection system for fixing a plurality of locations in the length direction of a sensing optical cable to a measurement target, detecting displacement generated in the measurement target as distortion of the sensing optical cable, and detecting the displacement generated in the measurement target A method of laying a sensing optical cable for laying the sensing optical cable,
At least one mounting base is directly or indirectly fixed to a measurement object, a sensing optical cable is sandwiched between a pair of corrugated members having corrugated concave and convex surfaces that fit together, and the clamper is directly attached to the mounting base. Or indirectly, it is engaged so as to be movable in the cable length direction, and the tension of the optical cable for sensing is adjusted by adjusting the movement of the clamper in the cable length direction with respect to the mounting base. How to lay optical cables. In a displacement detection system for fixing a plurality of locations in the length direction of a sensing optical cable to a measurement target, detecting displacement generated in the measurement target as distortion of the sensing optical cable, and detecting the displacement generated in the measurement target A method of laying a sensing optical cable for laying the sensing optical cable,
At least one mounting base is directly or indirectly fixed to the measurement target, and the sensing optical cable is sandwiched between a pair of corrugated members having corrugated concave and convex surfaces that fit together, and the clamper is held by a holding member. The holding member is engaged with the mounting base so as to be movable in the cable length direction, and an adjustment bolt in the cable length direction for engaging the holding member and the mounting base is provided to adjust the tension of the optical cable for sensing. In doing so, the position of the holding member in the cable length direction with respect to the mounting base of the holding member is adjusted by the adjusting bolt, and a method for laying the sensing optical cable is provided.

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