JP2005308535A - Planar body for detecting strain and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a planar body for detecting strain by utilizing an optical fiber, and its manufacturing method. <P>SOLUTION: In this planar body for detecting strain of a prescribed position, a protection tube 21 is integrated beforehand into a planar body material, and then the optical fiber 2 is arranged in the protection tube 21. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a planar body that detects strain using an optical fiber and a method for manufacturing the same.

As one of the methods for detecting the deformation of the embankment, a method using an optical fiber has been tried.
In this method, when embedding a planar body functioning as a fill reinforcement such as geogrid in the embankment, an optical fiber is buried together, and the change in the nature of the embedding is measured as a strain change of the buried optical fiber. is there.

The measurement technique combining the optical fiber and the planar body has the following problems.
(1) A suitable manufacturing technique for integrating an optical fiber and a planar body has not been proposed.
In particular, since an optical fiber is weak against heat, it is technically difficult to incorporate an optical fiber in the process of manufacturing a lattice-shaped planar body based on a melted planar body material.
(2) Although there is an invention in which a special optical fiber excellent in heat resistance is directly embedded when manufacturing a planar body (Japanese Patent Laid-Open No. 2002-122414), a special optical fiber excellent in heat resistance is a general optical fiber. Since it is very expensive, there is room for improvement in terms of practical use.
(3) Since an optical fiber is easily damaged, even if an optical fiber is retrofitted to the outside of the planar body, the optical fiber is displaced when it is displaced and cannot follow the displacement of the planar body, or the optical fiber is destroyed. Therefore, the method of retrofitting is not practical.
(4) For the above reasons, it has not yet been put into practical use in terms of cost and detection accuracy.

The present invention has been made in view of the above points, and an object thereof is to provide a planar body for detecting any one of the following distortions and a method for manufacturing the same.
(1) Practical use of assembling an optical fiber to a planar body.
(2) A planar body in which optical fibers are integrally assembled can be manufactured at low cost.
(3) The distortion can be accurately detected via the planar body.

The planar body for detecting strain according to the present invention is a planar body for detecting strain at a predetermined position, and a protective tube for storing an optical fiber is integrally incorporated in the planar body material. It is what.
Furthermore, the planar body for detecting strain according to the present invention is a planar body for detecting strain at a predetermined position, and includes a protective tube for inserting an optical fiber integrated into the planar body material, and the protection The optical fiber is inserted into the tube, and the optical fiber is inserted into the protective tube and integrated.
Further, in the planar body for detecting strain according to the present invention, the planar body material is integrated with the outer peripheral surface of the protective tube by self-adhesive force in the above-described planar body for detecting strain. It is what.
Furthermore, in the planar body for detecting strain according to the present invention, in the planar body for detecting any one of the above-described strains, the circumferential surface of the protective tube is formed in an uneven shape, and the planar body material and the circumferential surface of the protective tube are formed. The surface is in close contact and integrated.
Furthermore, the planar body for detecting strain according to the present invention is the above-described planar body for detecting strain, wherein a consolidated layer is formed by an adhesive between a protective tube and an optical fiber, and the consolidated layer The protective tube and the optical fiber are integrated with each other.
Also, the method for manufacturing a planar body for detecting strain according to the present invention provides a method for housing an optical fiber in a molten planar body material when forming a planar body by forming a molten planar body material into a lattice shape. For example, the protective tube is inserted and fixed integrally.
The method of manufacturing a planar body for detecting strain according to the present invention is for storing an optical fiber in a molten planar body material when forming the planar body by forming a molten planar body material into a lattice shape. The protective tube is inserted and fixed together, and the optical fiber is accommodated in the planar protective tube, and the protective tube and the optical fiber are integrated.
Furthermore, in the method for manufacturing a planar body for detecting strain according to the present invention, in any one of the above-described planar body manufacturing methods, the self-adhesive force of the melted planar body material is integrated with the outer peripheral surface of the protective tube. It is characterized by this.
Furthermore, the manufacturing method of a planar body for detecting strain according to the present invention is a planar body material that melts using a protective tube having a concavo-convex process on the peripheral surface in any of the above-described manufacturing methods of a planar body. The self-adhesive force is integrated with the outer peripheral surface having the uneven shape of the protective tube. In order to give the uneven shape of the protective tube, it can be formed by, for example, rotating the protective tube while pressing the protective tube with two or more rollers whose surface is processed to provide unevenness on the peripheral surface of the protective tube. .
Furthermore, the method for manufacturing a planar body according to the present invention is characterized in that, in any of the above-described methods for manufacturing a planar body, the protective tube and the optical fiber are integrated with each other by a consolidated layer using an adhesive. It is.
Each planar body described above is a reinforcing material, a drainage material, a civil engineering sheet, a filter, or a water shielding sheet.

The present invention can obtain at least one of the following effects.
(1) By adopting a configuration in which an optical fiber is arranged in the protective tube after the protective tube is integrated in advance into the planar material, the optical fiber can be assembled to the planar member in a room temperature environment. Thus, it becomes possible to put to practical use a planar body having a strain detection function incorporating an optical fiber, which has been difficult until now.
(2) Since the optical fiber can be assembled at room temperature rather than in a high temperature environment, a general inexpensive optical fiber can be used, and the manufacturing cost of the planar body for detecting strain can be greatly reduced.
(3) By integrating the three members of the planar body, the protective tube, and the optical fiber, the protective tube and the optical fiber can follow the displacement of the planar body, so that the strain detection accuracy is greatly improved.
In particular, when a protective tube having a concavo-convex process is used, the followability is improved as compared with a case where the concavo-convex process is not performed, and therefore the distortion detection accuracy is further improved.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
<1> Outline of strain detection technique FIG. 1 is a perspective view of a planar body 1 capable of detecting strain.
In the present invention, when the planar body 14 is manufactured, the protective tube 21 is integrally incorporated in the melted planar material, and the optical fiber 2 is later inserted into the protective tube 21 and integrated. Thus, the planar body 1 capable of detecting distortion can be obtained.
When a displacement such as deformation or extension occurs in the planar body 14, the force applied to the planar body 14 is transmitted as it is to the optical fiber 2 in the protective tube 21 via the protective tube 21. The fiber 2 is displaced following the planar body 14. By detecting the distortion of the optical fiber 2 electrically, the presence or absence of displacement of the planar body 14 and the amount of displacement are measured or monitored.

  Explaining about the planar body 1 capable of detecting the illustrated distortion, the planar body 14 has a protective tube 21. The end of the optical fiber 2 installed in the protective tube 21 is connected to the strain detection device 23. When a force acts on the planar body 1 and distortion occurs at a predetermined location of the protective tube 21, the position of the predetermined location and the amount of distortion can be measured by the strain detection device 23 via the optical fiber 2. As the optical fiber strain detection device 22, for example, “BOTDR” (manufactured by Ando Electric Co., Ltd.) can be used.

<2> Planar body main body The planar body main body 14 is a lattice-shaped body with objects in two or more directions and a space in between.
FIG. 1 shows a lattice-like planar body 14 that is generally used as a reinforcing material for embankments. The planar body 14 is formed by, for example, forming a longitudinal member 12 and a transverse member 11 mainly composed of a resin such as polyethylene in a lattice shape, and either one of the longitudinal member 12 or the transverse member 11 has an aramid fiber, A reinforcing wire 13 such as carbon fiber or glass fiber is used to increase the strength.
The protective tube 21 is attached so that it may be arrange | positioned in the required position which detects the distortion of a planar body. A method for installing the protective tube 21 will be described later.
The lattice-shaped planar body in FIG. 1 shows a form in which the protective tube 21 is arranged on a specific longitudinal member 12.
In addition to the above-described resin net material, the planar body main body 14 includes those formed of a thread-like material such as a net, a woven fabric, a knitted fabric or a non-woven fabric, and those formed in a plate shape. In addition to the rectangle such as a square or a rectangle, the overall shape may be a curved shape such as a circle or an ellipse, and there is no particular restriction on the shape.

<3> Protective tube The protective tube 21 is a protective member that is incorporated in the planar body main body 14 in advance to protect the optical fiber 2 from damage.
In this example, a mode in which the protective tube 21 is completely embedded in the planar body main body 14 will be described. However, as another mode to be incorporated in the planar body main body 14, the protective tube 21 is formed from the surface inside the planar body main body 14. A form in which a part is exposed and a form in which the protective tube 21 is entangled with the planar body 14 are also included. In any of the built-in configurations, an installation structure that can directly transmit distortion such as deformation and displacement of the planar body 14 to the protective tube 21 is preferable.
The protective tube 21 is capable of physically protecting the optical fiber accommodated therein, such as plastic or metal, from heat and external force, and easily receives distortion following the deformation and displacement of the planar body 14. A material of the nature is preferred.
In practice, the protective tube 21 is preferably a stainless steel tube.

The protective tube 21 is provided with a concavo-convex shape at least on the outer peripheral surface thereof, so that the integrity with the planar body main body 14 can be improved and the followability to deformation of the planar body main body 14 can be improved.
The concavo-convex shape is a shape such as a groove, a protrusion, or a hole, and is provided over the entire outer periphery of the protective tube 21, or a part thereof, or is distributed uniformly throughout. In short, any shape and structure that can increase the slip resistance between the protective tube 21 and the planar body 14 may be used.

<4> Uneven shape of protective tube The above-described uneven shape is provided only on the outer peripheral surface of the protective tube 21, and there are two forms of forming the inner peripheral surface smoothly and forming on the inner and outer surfaces of the protective tube 21.
In order to form the concavo-convex shape 211 on both the inner and outer surfaces of the protective tube 21, for example, by pressing the protective tube 21 from the outside and plastically deforming it, the inner surface of the protective tube 21 is also formed with an concavo-convex shape corresponding to the unevenness of the outer peripheral surface. can do.
In order to form the concavo-convex shape 211 on the protective tube 21, for example, as shown in FIG. 2, it can be formed using a processing apparatus provided with a plurality of molding rollers 51.
The forming roller 51 is a rotating roller having a tooth shape formed on the outer peripheral surface. The two rollers 51 are arranged to face each other, and are arranged at a smaller interval than the outer diameter of the protective tube 21 before forming. is there.
FIG. 2 shows a case where a pair of forming rollers 51 is arranged and the concave and convex shape 211 is formed in two directions of the protective tube 21 while sandwiching and pressing the protective tube 21, and FIG. 3 shows two sets of forming rollers 51 arranged. Then, the case where the concave and convex shape 211 is formed on the four sides of the protective tube 21 is shown.
The number of sets of the forming rollers 51 and the tooth shape are appropriately selected.

<5> Installation Method of Protective Tube In this example, a case where the protective tube 21 is incorporated together when the planar body 14 is manufactured will be described.
FIG. 6 is a model diagram of the planar body manufacturing apparatus 4 that manufactures the planar body body 14, and a planar body material such as resin is accommodated in a molten state in the container 4. The forming portion 42 is located, and a winding drum 43 is provided in front of the forming portion 42.
Behind the formation part 42, the protective tube 21 having one or a plurality of concave and convex processes and the reinforcing wire 13 (not shown) can be continuously supplied into the formation part 42.
When the planar material in the molten state in the container 4 is supplied to the forming portion 42 and formed into a net shape inside the forming portion 42, the protective tube 21 is placed in the longitudinal direction inside the planar body 14 in the molten state. Buried toward The molten planar sheet body 14 in which the protective tube 21 is embedded is wound around the winding drum 43 through forced cooling by water cooling or air cooling.

By embedding the protective tube 21 with the uneven shape 211 in this way when the planar body main body 14 is manufactured, the protective tube 21 is bonded to the outer peripheral surface of the protective tube 21 by the self-adhesive force of the material of the planar body main body 14. Integrate. In particular, as shown in FIG. 4, if there is an uneven shape 211 on the outer peripheral surface of the protective tube 21, the base materials of the planar body 14 will bite into each other and the degree of adhesion will further increase. Compared with the case where the protective tube 21 is not provided with a concavo-convex shape, the extraction resistance between the protective tube 21 and the planar body is substantially integrated.
In addition, the uneven | corrugated process of the protective tube 21 may be performed in parallel with the process which manufactures the planar body 14, or the protective tube 21 which gave the uneven | corrugated process previously may be used.

The optical fiber 2 is assembled with the planar body 14 manufactured by incorporating the protective tube 21 as a target. That is, the optical fiber 2 is inserted into the protective tube 21 and fixed integrally to obtain the planar body 1 that can detect strain.
As a means for fixing the protective tube 21 and the optical fiber 2, means such as adhesion and press-fitting can be applied. In practice, an adhesive may be applied to the optical fiber 2 immediately before insertion. When using an adhesive, it is advisable to add a solidification retarder to the adhesive to lengthen the consolidation time so that it does not solidify during insertion.

As described above, since the optical fiber 2 is inserted into the protective tube 21 later and integrated, the optical fiber 2 is not affected by the heat (melting heat) generated when the planar body 14 is manufactured. Can be set.
In particular, as shown in FIG. 5, when the optical fiber 2 is fixed through an adhesive in a protective tube 21 having irregularities on both the inner and outer surfaces, the optical fiber 21 and the adhesive consolidation layer 22 are firmly fixed. In addition, the adhesive consolidated layer 22 can bite into the concave-convex shape 211 of the protective tube 21 so that the members 21 and 22 can be more firmly fixed.

<6> Example of Usage Method An example of usage method of the planar body 1 capable of detecting distortion is shown in FIG.
The planar body 1 capable of detecting strain is laid horizontally in the embankment 3 as a bank reinforcement, and the optical fiber 2 extending from the planar body 1 capable of detecting strain of each layer is connected to a known strain detector 23.
The planar body 1 capable of detecting strain has a function of measuring the displacement of the embankment 3 in addition to the original reinforcing function of restraining the soil and restraining the slip of the embankment 3.
In other words, sediment movement occurs when there is a sign of land subsidence or sediment collapse. When the earth and sand movement occurs, a tensile force and a contraction force act on the planar body 1 that can detect the strain at the location. As a result, distortion occurs in the protective tube 21 and the optical fiber 2 at the predetermined positions.

By measuring the displacement of the optical fiber 2 with the strain detection device 22, it is possible to observe where the soil displacement occurs in the embankment 3.
Moreover, the distortion | strain of the whole embankment can be observed by arrange | positioning the planar body 1 which can detect distortion on the embankment 3 in layers.

Although the planar body 1 capable of detecting strain is shown in FIG. 7 as a case where it is used as a bank reinforcement, a planar body made of a civil engineering material such as a drainage material, a civil engineering sheet, a filter, or a water shielding sheet may be used. For example, it can be used as a strain gauge together with these original functions.
The planar body 1 capable of detecting strain may be used only for measuring strain in various civil engineering works such as tunnels, dikes, and dams.

<7> Other Embodiments FIGS. 8 and 9 show the case where the protective tube 211 is incorporated in the planar body main body 14 without providing an uneven shape, and the optical fiber 2 is accommodated in the protective tube 211 not provided with the uneven shape. Then, the case where the planar body 1 capable of detecting the distortion is formed will be shown.

In the above description, the protective tube 21 is assembled in advance and the optical fiber 2 is inserted and set later. However, the optical fiber 2 is inserted in the protective tube 21 in advance and the optical fiber 2 is inserted. The protective tube 21 may be incorporated together when the planar body 14 is manufactured. In this case, it is necessary to use a material having a heat insulating property (low thermal conductivity) that can protect the optical fiber 2 from the heat of fusion for the protective tube 21.

Explanatory drawing of a planar object that can detect lattice distortion Explanatory drawing of a processing device that forms irregular shapes on a protective tube Explanatory drawing of other processing equipment that forms irregularities on the protective tube Cross-sectional view of a planar body with a protective tube embedded Cross-sectional view of planar body with optical fiber in protective tube Explanatory drawing of the manufacturing method of a planar object which can detect lattice distortion Explanatory drawing applying a planar object that can detect strain to the measurement of embankment displacement Cross-sectional view of a planar body containing an optical fiber in a protective tube without irregularities Explanatory drawing of a planar body that can detect grid-like distortion without irregularities

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Plane body 11 which can detect distortion | strain ... Cross member 12 ... Vertical member 13 ... Reinforcement wire 14 ... Plane body main body 2 ... Optical fiber 21 ... Protective tube 211 -Adhesive consolidated layer 23-Optical fiber strain detector 3-Embankment 4-Planar body manufacturing device 41-Container 42-Forming part 43-Winding drum 5-Processing Device 51..Forming roller

Claims (10)

A planar body for detecting distortion at a predetermined position,
A protective tube for optical fiber storage is integrated into the planar material,
Planar body that detects distortion. A planar body for detecting distortion at a predetermined position,
A protective tube for inserting an optical fiber integrated into the planar material; and
An optical fiber inserted into the protective tube,
It is characterized by inserting and integrating an optical fiber into a protective tube,
Planar body that detects distortion.   The planar body for detecting strain according to claim 1 or 2, wherein the planar body material is integrated with the outer peripheral surface of the protective tube by self-adhesive force. body.   The planar body for detecting distortion according to claim 1 or 2, wherein the circumferential surface of the protective tube is formed in an uneven shape, and the planar body material and the circumferential surface of the protective tube are in close contact and integrated. A planar body for detecting distortion, characterized in that   The planar body for detecting strain according to any one of claims 2 to 4, wherein a consolidating layer is formed between the protective tube and the optical fiber by an adhesive, and the protective tube is interposed through the consolidating layer. A planar body for detecting strain, characterized in that optical fibers are integrated. A method of manufacturing a planar body for detecting distortion,
A strain characterized by inserting a protective tube for housing an optical fiber into the molten planar material and fixing it integrally when forming the planar body by forming a lattice of molten planar material. A method for producing a planar body for detecting odor. A method of manufacturing a planar body for detecting distortion,
When forming a planar body by making the melted planar body material into a lattice shape, a protective tube for storing an optical fiber is inserted into the melted planar body material and fixed together.
An optical fiber is housed in the protective tube of the planar body, and the protective tube and the optical fiber are integrated,
A method of manufacturing a planar body for detecting distortion.   The method for manufacturing a planar body for detecting strain according to claim 6 or 7, wherein the strain is integrated with the outer peripheral surface of the protective tube by the self-adhesive force of the melted planar body material. Manufacturing method of planar body to be detected.   9. The method for manufacturing a planar body for detecting strain according to claim 7 or 8, wherein a protective tube having an uneven surface is used, and the protective tube is formed by self-adhesive force of the melted planar body material. A method for producing a planar body for detecting distortion, characterized by being integrated with an outer peripheral surface having a concave-convex shape.   10. The method for manufacturing a planar body for detecting strain according to claim 7, wherein the protective tube and the optical fiber are integrated with each other by a bonding layer made of an adhesive. A method for producing a planar body for detecting odor.

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