Measuring device, measuring method, method for manufacturing a measuring device

Abstract

The objective is to provide a measuring device capable of measuring one or more parameters selected from strain, temperature, and vibration over a wide range. [Solution] The measuring section includes an optical fiber arrangement section having a surface shape, The measuring unit comprises an optical fiber arranged within the optical fiber arrangement section and a linear protective member. A measuring device in which at least a portion of the optical fiber is arranged along the longitudinal side of the protective member and a portion of its surface is covered by the protective member.

Description

[Technical Field]

[0001] The present disclosure relates to a measuring device, a measuring method, and a method for manufacturing a measuring device. [Background Art]

[0002] Patent Document 1 discloses an inclination measuring device comprising: a first fixed base fixed to a ground surface or a structure surface serving as a measurement point; an inclination sensor, one end of which is rotatably supported by the first fixed base; a detection rod attached to the other end of the inclination sensor; and a second fixed base that supports a slide sleeve in which the other end of the detection rod is slidably accommodated, wherein the inclination of the detection rod is angle-detected by the inclination sensor. [Prior Art Literature] [Patent Literature]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 2005-181176 [Summary of Invention] [Problem to be Solved by the Invention]

[0004] As disclosed in Patent Document 1, measuring devices for measuring the state of ground such as slopes and detecting occurrences of landslides have been conventionally used.

[0005] However, conventional measuring devices can often only perform local measurement in many cases, and it has been necessary to install a plurality of measuring devices in order to grasp the state of ground such as slopes. For this reason, it has not been possible to perform measurement over a wide range of slopes and the like.

[0006] Accordingly, an object of the present disclosure is to provide a measuring device capable of measuring one or more types selected from strain, temperature, and vibration over a wide range. [Means for Solving the Problem]

[0007] The measuring device of the present disclosure has a measuring section including an optical fiber arrangement section having a planar shape, the measuring section having optical fibers arranged within the optical fiber arrangement section and a linear protective member, at least a portion of the optical fibers being arranged along the longitudinal side of the protective member and a portion of its surface being covered by the protective member. [Effects of the Invention]

[0008] According to this disclosure, a measuring device capable of measuring one or more selected from strain, temperature, and vibration over a wide range can be provided. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a perspective view of a measuring device according to one embodiment of this disclosure, installed on a slope. [Figure 2] Figure 2 is a schematic diagram of a modified example of the optical fiber arrangement when the optical fiber arrangement section is viewed along block arrow A in Figure 1. [Figure 3] Figure 3 is an explanatory diagram illustrating the case where an optical fiber has bends along its longitudinal direction at regular intervals. [Figure 4A] Figure 4A is a schematic cross-sectional view of the protective member and optical fiber when the optical fiber is installed in the protective member, with the view taken from a plane perpendicular to the longitudinal direction of the protective member and the optical fiber. [Figure 4B] Figure 4B is a schematic cross-sectional view of the protective member and optical fiber when the optical fiber is installed in the protective member, with the view taken from a plane perpendicular to the longitudinal direction of the protective member and the optical fiber. [Figure 4C] Figure 4C is a schematic cross-sectional view of the protective member and optical fiber when the optical fiber is installed in the protective member, with the view taken from a plane perpendicular to the longitudinal direction of the protective member and the optical fiber. [Figure 5A] Figure 5A is an explanatory diagram of the fixing member when the optical fiber arrangement section is viewed along block arrow A in Figure 1. [Figure 5B] Figure 5B is an explanatory diagram of the fixing member when the optical fiber arrangement section is viewed along block arrow A in Figure 1. [Figure 6]Figure 6 is a schematic cross-sectional view of the measurement device along line BB in Figure 1, when the measuring device is located within a concrete structure. [Modes for carrying out the invention]

[0010] The implementation methods are described below.

[0011] [Description of Embodiments in this Disclosure] The embodiments of this disclosure are first listed and described. In the following description, the same or corresponding elements are denoted by the same reference numerals, and the same description of them is not repeated.

[0012] (1) A measuring device according to one aspect of the present disclosure has a measuring section including an optical fiber arrangement section having a planar shape, the measuring section having optical fibers arranged in the optical fiber arrangement section and a linear protective member, at least a portion of the optical fibers being arranged along the longitudinal side of the protective member and a portion of the surface being covered by the protective member.

[0013] A measuring device according to one aspect of this disclosure has a measuring section that includes a surface-shaped optical fiber arrangement section, and therefore the optical fiber arrangement section can be installed, for example, on a slope, and measurements can be performed. The optical fiber arranged in the optical fiber arrangement section can measure one or more measurements selected from strain, temperature, and vibration along the longitudinal direction of the optical fiber. For this reason, the measuring device according to one aspect of this disclosure can measure one or more measurements selected from strain, temperature, and vibration over a wide area of ​​the entire optical fiber arrangement section in which the optical fiber is arranged. One or more measurements selected from strain, temperature, and vibration will also be referred to as "strain, etc." below.

[0014] The measuring unit has a protective member, and at least a portion of the optical fiber is positioned along the longitudinal side of the protective member, so that a portion of the surface of the optical fiber is covered by the protective member, thereby preventing damage to the optical fiber.

[0015] (2) In the above (1), the optical fiber may have a plurality of folded portions within the optical fiber arrangement portion.

[0016] Since the optical fiber has a plurality of folded portions and is arranged within the optical fiber arrangement portion, a single optical fiber can be arranged in a planar shape. Therefore, strain and the like can be measured over a wide range by a single optical fiber, and the number of scattered light measurement devices required for measurement can also be reduced.

[0017] (3) In the above (1) or (2), the measurement section includes a plurality of said optical fibers, and when said optical fiber arrangement portion is viewed from vertically above the optical fiber arrangement portion, at least portions of the plurality of said optical fibers may be arranged so as to intersect each other.

[0018] Since the measurement section includes a plurality of optical fibers, and at least portions of the plurality of optical fibers are arranged so as to intersect each other in the optical fiber arrangement portion, the optical fibers can be arranged to form a plane, and measurement of strain and the like can be performed without omission across the entire optical fiber arrangement portion.

[0019] (4) In any one of the above (1) to (3), the protective member includes a stranded wire formed by stranding metal element wires, and the optical fiber may be arranged in a strand groove of the stranded wire.

[0020] By forming the protective member as a stranded wire, it can be easily bent. Therefore, the protective member having the optical fiber arranged therein can be easily deformed according to the shape of the optical fiber arrangement portion, and the optical fiber can be easily routed throughout the inside of the optical fiber arrangement portion.

[0021] Furthermore, by arranging the optical fiber in the strand groove of the stranded wire formed by stranding metal element wires that serves as the protective member, the optical fiber can be protected and breakage and the like can be prevented.

[0022] (5) In any of (1) to (4) above, the measuring unit may have a fixing member that fixes at least a portion of the optical fiber within the optical fiber arrangement unit.

[0023] Since at least a portion of the optical fiber is fixed by a fixing member, displacement of the optical fiber within the optical fiber arrangement area after installation can be prevented. Therefore, the positional accuracy when measuring strain and other parameters after the optical fiber has been installed can be improved.

[0024] (6) In the above (5), when the optical fiber arrangement section is viewed from above in the vertical direction of the optical fiber arrangement section, the fixing member may have at least a part of a grid shape.

[0025] If the fixing member has a grid shape, the number of points of contact between the fixing member and the optical fiber can be increased, making it easier to fix the optical fiber to the fixing member.

[0026] (7) In any of (1) to (6) above, the measuring unit may further include a scattered light measuring device connected to the optical fiber.

[0027] The measurement unit has a scattered light measuring device connected to the optical fiber, allowing for easy measurement of strain and other parameters along the length of the optical fiber. The scattered light measuring device does not need to be constantly connected to the optical fiber; it can be detached and connected only during measurement.

[0028] (8) In any of (1) to (7) above, the optical fiber arrangement unit is arranged along the surface of the slope and may further include a calculation unit that calculates a measurement value including one or more selected from strain, temperature, and vibration on the slope from the measurement results of the measurement unit.

[0029] A measuring device according to one aspect of this disclosure has a calculation unit, which makes it possible to easily calculate strains and other factors over a wide area within the slope measured by the measuring unit.

[0030] (9) In (8) above, the measuring unit may perform measurements multiple times at predetermined timings, and the calculation unit may calculate the change over time of the measured value on the slope.

[0031] The measurement unit performs multiple measurements, and the calculation unit calculates the change in the measured values ​​over time. This makes it possible to evaluate the changes in the condition of slopes and, in the case of concrete structures installed on slopes, concrete structures, based on the measured values.

[0032] (10) The above (9) may further include an alarm unit that issues an alarm when the range of change over time of the measured value of the slope calculated by the calculation unit exceeds a specified value.

[0033] The measuring device according to one aspect of this disclosure has an alarm unit, which makes it possible to quickly notify the operator or manager, etc., if a problem occurs in the condition of the slope.

[0034] (11) In any of (1) to (10) above, there may be a recording unit that records positional information of the optical fibers in the optical fiber arrangement section on the slope, and a first position identification unit that identifies the position on the slope where the measured value was obtained, calculated by the calculation unit based on the positional information of the optical fibers held by the recording unit.

[0035] The recording unit records the positional information of the optical fibers on the slope, and the calculation unit identifies the location where the measured values ​​of the slope were obtained based on the optical fiber positional information, thereby enabling particularly accurate evaluation of the slope's condition.

[0036] (12) In any of (1) to (11) above, the optical fiber may have bends along its longitudinal direction at regular intervals, and may have a second position identification unit that identifies the position of the bends in the measurement data measured by the measurement unit and identifies the position where the measurement value of the slope calculated by the calculation unit is obtained.

[0037] Because optical fibers have bends at regular intervals along their length, the strain originating from these bends is reflected in the measurement data. Therefore, the measurement unit can identify the location of the bends along the length of the optical fiber in the measurement data it has collected. By then using the identified bend locations to pinpoint the locations where the slope measurement values ​​calculated by the calculation unit were obtained, the condition of the slope can be evaluated with particular accuracy.

[0038] (13) A measurement method according to one aspect of the present disclosure comprises a measurement step of measuring a measurement value on a slope, including one or more selected from strain, temperature, and vibration, wherein the measurement device comprises a measurement section including an optical fiber arrangement section having a surface shape arranged along the surface of the slope and a scattered light measuring device, wherein the measurement section comprises an optical fiber arranged in the optical fiber arrangement section and a linear protective member, wherein at least a portion of the optical fiber is arranged along the longitudinal side of the protective member and a portion of its surface is covered by the protective member, the optical fiber is connected to the scattered light measuring device, and in the measurement step, scattered light is emitted from the scattered light measuring device to the optical fiber and the measurement value on the slope along the longitudinal side of the optical fiber is measured.

[0039] A measurement method according to one aspect of this disclosure has a measurement unit that includes an optical fiber arrangement unit having a planar shape, so that the optical fiber arrangement unit can be installed, for example, on a slope, and measurements can be performed. In the measurement process, the optical fiber arranged in the optical fiber arrangement unit can measure one or more measurements selected from strain, temperature, and vibration along the longitudinal direction of the optical fiber. Therefore, a measurement method according to one aspect of this disclosure can measure one or more measurements selected from strain, temperature, and vibration over a wide area of ​​the entire optical fiber arrangement unit in which the optical fiber is arranged.

[0040] Furthermore, the measuring unit has a protective member, and at least a portion of the optical fiber is positioned along the longitudinal side of the protective member, thereby covering a portion of the optical fiber's surface with the protective member, preventing damage to the optical fiber.

[0041] (14) In (13) above, the slope and the optical fiber arrangement area are covered by a concrete structure, and the measurement step may include a first determination step in which the measured value along the longitudinal direction of the optical fiber is measured multiple times at predetermined intervals using the optical fiber, and the presence or absence of deformation in the concrete structure is determined from the change over time of the measured value along the longitudinal direction of the optical fiber measured in the measurement step.

[0042] When a concrete structure deforms, it affects the time-dependent changes in measurements along the longitudinal direction of the optical fiber, such as strain and temperature distribution. Therefore, by measuring the time-dependent changes in the distribution of measurements such as strain and temperature along the longitudinal direction of the optical fiber, it is possible to determine whether or not the concrete structure has deformed.

[0043] (15) In (13) above, the measurement unit has at least two optical fibers arranged in parallel within the optical fiber arrangement unit, the slope and the optical fiber arrangement unit are covered by a concrete structure, and the measurement step may include a second determination step in which the strain along the longitudinal direction of the optical fibers is measured using at least two optical fibers arranged in parallel, and if the difference in strain measured using at least two optical fibers arranged in parallel is greater than or equal to a predetermined value, it is determined that deformation has occurred in the concrete structure.

[0044] The strain and strain distribution measured using at least two parallel optical fibers will be nearly identical unless a large external force is applied to the optical fibers causing deformation. Therefore, if the difference in strain and strain distribution measured using at least two parallel optical fibers is large, it means that the optical fibers are significantly bent. Consequently, if the difference in strain and strain distribution measured using at least two optical fibers becomes large, it can be determined that deformation has occurred in, for example, a concrete structure installed to cover a slope.

[0045] (16) In any of (13) to (15) above, the slope and the optical fiber arrangement area are covered by a concrete structure, and the measurement step may include a third determination step in which the vibration along the longitudinal direction of the optical fiber on the slope is measured using the optical fiber, and the presence or absence of a cavity between the concrete structure and the slope is determined from the distribution of the vibration along the longitudinal direction of the optical fiber measured in the measurement step.

[0046] When a slope is covered with a concrete structure, water infiltration due to rain can cause soil erosion, potentially creating voids between the concrete structure and the soil. Since the presence of these voids alters the vibration pattern, measuring the vibration distribution along the length of an optical fiber can determine the presence or absence of voids between the concrete structure and the slope.

[0047] (17) In any of (13) to (16) above, the slope and the optical fiber arrangement area are covered by a concrete structure, and the measurement step may include a fourth determination step in which the temperature along the longitudinal direction of the optical fiber on the slope is measured multiple times at predetermined intervals using the optical fiber, and the presence or absence of a cavity between the concrete structure and the slope is determined from the change in temperature along the longitudinal direction of the optical fiber measured in the measurement step over time.

[0048] Slopes covered with concrete structures can experience soil erosion due to water infiltration from rain, creating voids between the concrete structure and the soil. Since these voids affect the temperature distribution over time, measuring the change in temperature distribution along the length of an optical fiber over time can determine whether or not there are voids between the concrete structure and the slope.

[0049] (18) A method for manufacturing a measuring device according to one aspect of the present disclosure comprises: an optical fiber arrangement step of arranging optical fibers along the surface of a slope to form an optical fiber arrangement section having a planar shape; and an optical fiber position recording step of recording the position of the optical fibers in the optical fiber arrangement section, wherein the optical fiber arrangement section further has a linear protective member, at least a portion of the optical fiber is arranged along the longitudinal side of the protective member, and a portion of its surface is covered by the protective member.

[0050] According to a method for manufacturing a measuring device according to one aspect of this disclosure, a measuring device can be manufactured having a measuring section equipped with a planar optical fiber arrangement section that includes optical fibers arranged along the surface of a slope. Therefore, according to a method for manufacturing a measuring device according to one aspect of this disclosure, a measuring device can be manufactured that can measure one or more measurements selected from strain, temperature, and vibration over a wide area of ​​the entire optical fiber arrangement section in which the optical fibers are arranged.

[0051] Furthermore, the measuring unit has a protective member, and at least a portion of the optical fiber is positioned along the longitudinal side of the protective member, thereby covering a portion of the optical fiber's surface with the protective member, preventing damage to the optical fiber.

[0052] [Details of the embodiments of this disclosure] Specific examples of a measuring device, measuring method, and method for manufacturing a measuring device according to one embodiment of this disclosure (hereinafter referred to as "this embodiment") will be described below with reference to the drawings. However, the present invention is not limited to these examples and is intended to be shown in the claims, with all modifications within the meaning and scope of equivalence to the claims included.

[0053] In this specification, the names of components may be described with prefixes such as "1st," "2nd," etc. For example, they may be described as "1st position identification part," "2nd position identification part," etc. The prefixes "1st" and "2nd" added to the position identification parts are merely used to identify each component and prevent confusion during description, and do not indicate arrangement or priority. When there is no risk of confusion or when referring collectively, the term "position identification part" may be used.

[0054] [1] Measuring device An example of the configuration of the measuring device of this embodiment will be explained with reference to Figures 1, 2, 3, 4A, 4B, 4C, 5A, 5B, and 6.

[0055] Figure 1 is a perspective view of the measuring device of this embodiment installed on a slope.

[0056] Figure 2 is a schematic diagram of a modified example of the optical fiber arrangement when the optical fiber arrangement section is viewed along block arrow A in Figure 1.

[0057] Figure 3 is an explanatory diagram illustrating the case where an optical fiber has bends along its longitudinal direction at regular intervals.

[0058] Figures 4A, 4B, and 4C are schematic cross-sectional views of the protective member and optical fiber when the optical fiber is installed in the protective member, viewed from a plane perpendicular to the longitudinal direction of the protective member and the optical fiber.

[0059] Figures 5A and 5B are explanatory diagrams of the fixing members when the optical fiber arrangement section is viewed along block arrow A in Figure 1.

[0060] Figure 6 is a schematic cross-sectional view of the measurement device along line BB in Figure 1, when the measuring device is located within a concrete structure. Figure 4 is a cross-sectional view of the optical fiber in a plane perpendicular to its longitudinal side, when the measuring device of this embodiment has a protective member.

[0061] The measuring device 10 of this embodiment may have a measuring unit 11 that includes a surface-shaped optical fiber arrangement section 111. The measuring unit 11 may have optical fibers 12 arranged within the optical fiber arrangement section 111. The measuring unit 11 can measure measurement values ​​(parameters) including one or more selected from strain, temperature, and vibration using the optical fibers 12.

[0062] The measuring device 10 of this embodiment has a measuring unit 11 that includes a surface-shaped optical fiber arrangement unit 111, so that the optical fiber arrangement unit 111 can be installed, for example, on a slope 100, and measurements can be performed. Then, by using the optical fibers 12 arranged in the optical fiber arrangement unit 111, it is possible to measure one or more measurements selected from strain, temperature, and vibration along the longitudinal direction of the optical fiber. For this reason, the measuring device 10 of this embodiment can measure one or more measurements selected from strain, temperature, and vibration over a wide area of ​​the entire optical fiber arrangement unit in which the optical fibers are arranged.

[0063] In this specification, "slope" means a slope, and includes, for example, artificial slopes created by cutting or filling. (1) Optical fiber arrangement section (1-1) Arrangement of optical fibers in the optical fiber layout section The optical fiber arrangement section 111 refers to a virtual area where the optical fibers 12 are arranged, and it is not necessary to define the optical fiber arrangement section 111 as a specific component. The arrangement of the optical fibers 12 in the optical fiber arrangement section 111 is not particularly limited, but as shown in Figure 1, for example, the optical fibers 12 may have multiple folded portions 120 within the optical fiber arrangement section 111.

[0064] Since the optical fiber 12 has multiple folded sections 120 and is arranged within the optical fiber arrangement section 111, a single optical fiber can be arranged in a planar manner. Therefore, strain and other parameters can be measured over a wide area using a single optical fiber, and the number of scattered light measuring devices 112 required for measurement can also be reduced.

[0065] Furthermore, the measurement unit 11 may have multiple optical fibers 12. If the measurement unit 11 has multiple optical fibers 12, when the optical fiber arrangement unit 111 is viewed from above in the vertical direction, the multiple optical fibers 12 may be arranged so that at least some of them intersect with each other.

[0066] Figure 2 shows a schematic diagram of a modified arrangement of optical fibers 12, as viewed from above the optical fiber arrangement section 111 in the vertical direction, i.e., along block arrow A in Figure 1. As shown in Figure 2, the measurement section 11 may have multiple optical fibers 12. Figure 2 shows an example with vertically arranged optical fibers 12A and horizontally arranged optical fibers 12B, but the measurement section 11 is not limited to this configuration, and may have, for example, only optical fibers 12A or optical fibers 12B.

[0067] For example, as shown in Figure 2, when the optical fiber arrangement section 111 is viewed from above in the vertical direction, the multiple optical fibers 12 may be arranged so that at least some of them intersect with each other.

[0068] The measurement unit 11 has multiple optical fibers 12, and in the optical fiber arrangement unit 111, the optical fibers can be arranged to form a surface by arranging at least some of the multiple optical fibers 12 so that they intersect with each other. Therefore, strain and other measurements can be performed without omission across the entire optical fiber arrangement unit 111. (1-2) About optical fibers As the optical fiber 12, for example, one having a core and a cladding may be used. Examples of materials for the core and cladding include plastic and quartz glass. As the optical fiber, one or more types selected from optical fiber strands having a primary coating on the outer circumference of the cladding, optical fiber cores having a secondary coating, and optical fiber cords having a reinforcing material on the outer circumference of the secondary coating and an outer sheath covering the outer circumference of the reinforcing material may be used.

[0069] Examples of primary coating materials include UV-curing resins. Examples of secondary coating materials include flame-retardant polyester elastomers. Examples of reinforcing materials include glass fibers, carbon fibers, and aramid fibers. Examples of outer covering materials include flame-retardant polyolefins such as flame-retardant polyethylene, flame-retardant crosslinked polyolefins such as flame-retardant crosslinked polyethylene, and heat-resistant vinyl.

[0070] The type of optical fiber used is not particularly limited and can be selected according to the type of measurement parameter to be measured (such as strain), the measurement method, and the type of scattered light used during measurement. For example, one or more types of optical fibers selected from single-mode optical fibers, multimode optical fibers, and polarization-maintaining optical fibers may be used.

[0071] The outer diameter of the optical fiber 12 is not particularly limited, but for example, it may be 1.5 mm or less, or 1.0 mm or less.

[0072] By making the outer diameter of the optical fiber 12 1.5 mm or less, the installation of the optical fiber 12 can be easily performed. Furthermore, the optical fiber 12 may be placed in the groove 42 of the protective member 41, but this prevents the size of the groove 42 from becoming excessively large.

[0073] The lower limit of the outer diameter of the optical fiber 12 is not particularly limited, but the outer diameter of the optical fiber 12 may be 0.235 mm or more, or 0.8 mm or more. The durability of the optical fiber 12 can be increased by making the outer diameter of the optical fiber 12 0.235 mm or more. When the optical fiber 12 is installed and fixed on a measurement surface such as a slope, heat and external forces may be applied to the optical fiber, but by making the outer diameter of the optical fiber 12 0.235 mm or more, damage to the optical fiber 12 during installation can be prevented.

[0074] As shown in Figure 3, the optical fiber 12 may also have bends 31 along its length at regular intervals. That is, the optical fiber 12 may have bends 31 periodically such that the distance L31 between bends 31 is constant.

[0075] Since the optical fiber 12 has bends 31 along its longitudinal direction at regular intervals, the strain originating from the bends 31 is reflected in the measurement data measured using the optical fiber 12. Therefore, the location of the bends 31 along the longitudinal direction of the optical fiber 12 can be identified in the measurement data measured using the optical fiber 12. By then identifying the location where the measurement value was obtained based on the identified location of the bends 31, the measurement can be performed with particular accuracy. (1-3) Regarding protective components As shown in Figures 4A, 4B, and 4C, the measuring section 11 may further have a linear protective member 41. Figures 4A, 4B, and 4C are all cross-sectional views of the protective member 41 and the optical fiber 12 in a plane perpendicular to the longitudinal side.

[0076] If the measuring unit 11 has a protective member 41, at least a portion of the optical fiber 12 may be positioned along the longitudinal side of the protective member 41, and a portion of the surface of the optical fiber 12 may be covered by the protective member 41.

[0077] The measuring unit 11 has a protective member 41, and at least a portion of the optical fiber 12 is positioned along the longitudinal side of the protective member 41, so that a portion of the surface of the optical fiber 12 is covered by the protective member 41, thereby preventing damage to the optical fiber 12.

[0078] Therefore, the protective member 41 may have a groove or cavity that serves as an optical fiber housing for arranging the optical fiber 12.

[0079] As shown in Figure 4A, the protective member 41 may have a groove 42 along its longitudinal side, and the optical fiber 12 may be housed in the groove 42.

[0080] Furthermore, as shown in Figure 4B, the protective member 41 may have a columnar cavity 43 along its longitudinal side. In the case of Figure 4B, the optical fiber 12 is placed inside the cavity 43 of the protective member 41, so the optical fiber 12 is completely covered by the protective member 41.

[0081] As shown in Figure 4C, the protective member 41 includes a stranded wire 44 made by twisting together individual wires 441, and the optical fiber 12 may be placed in the twist groove 45 of the stranded wire 44.

[0082] By making the protective member 41 a stranded wire 44, it can be easily bent. Therefore, the protective member 41 on which the optical fibers 12 are arranged can be easily deformed to match the shape of the optical fiber arrangement section 111, and the optical fibers can be easily laid out within the optical fiber arrangement section 111.

[0083] If the protective member 41 includes stranded wire 44, the material of the individual wires 441 is not particularly limited and may be made of resin or metal. However, from the viewpoint of increasing the toughness of the protective member 41, the individual wires 441 may be made of metal. For this reason, the protective member 41 may include stranded wire 44 made by twisting together metal individual wires 441, and the optical fiber 12 may be placed in the twist grooves 45 of the stranded wire 44.

[0084] Even when the strands 441 are made of metal, i.e., when the protective member 41 is a metal wire, the inclusion of strands 44 in the protective member 41 allows it to be easily bent. Therefore, the protective member 41 on which the optical fibers 12 are arranged can be easily deformed to match the shape of the optical fiber arrangement section 111, allowing the optical fibers to be easily laid within the optical fiber arrangement section 111.

[0085] Furthermore, by placing the optical fiber 12 in the twist groove 45 of the stranded wire 44, which is made up of twisted metal strands 441 that serve as a protective member 41, the optical fiber 12 can be protected and prevented from being damaged.

[0086] As shown in Figure 4C, the optical fiber 12 may be arranged so that it is entirely contained within a region enclosed by a tangent L40 of two adjacent strands 441 along the outer circumference of the stranded wire 44, and two adjacent strands 441 along the outer circumference of the stranded wire 44. The tangent L40 is a tangent that is in contact with the outer circumference of the stranded wire 44. The two strands 441 that form the above region are the two strands 441 that are in contact with the tangent L40.

[0087] By positioning the optical fiber 12 within the region enclosed by the tangent L40 and two adjacent strands 441 along the outer circumference of the stranded wire 44, the optical fiber 12 is protected by the two strands 441, making it difficult for other components to directly contact the optical fiber 12. As a result, external forces are less likely to be directly applied to the optical fiber 12, and damage to the optical fiber 12 can be particularly prevented.

[0088] As shown in Figures 4A and 4C, by exposing a portion of the optical fiber 12 while a portion of the optical fiber 12 is covered by the protective member 41, the optical fiber 12 can be easily taken out at any point on the protective member 41 and connected using a scattered light measuring device. Furthermore, even if the optical fiber 12 is cut, for example, reconnection work becomes easier.

[0089] The number of strands 441 in the stranded wire 44 and its structure are not particularly limited. For example, the number of strands 441 in the stranded wire 44 may be 7 or 19. When the number of strands 441 in the stranded wire 44 is 7, the structure of the stranded wire 44 can be a single-layer stranded structure in which 6 outer strands 441B are spirally twisted around a single central strand 341A, as shown in Figure 4C. In this case, the outer strands 441B are located on the outermost edge of the stranded wire 44. Figure 2A shows an example in which the central strand 441A and the outer strands 441B have the same strand diameter, but the form is not limited to this. For example, the strand diameter of the central strand 441A and the strand diameter of the outer strands 441B may be different.

[0090] The material of the protective member 41 is not particularly limited, but it can be made of metal in order to protect the optical fiber 12. The type of metal used for the protective member 41 is not particularly limited, but one or more types selected from, for example, aluminum, aluminum alloy, steel, etc. can be used.

[0091] By making the protective member 41 out of metal, the toughness of the protective member 41 is increased, making it particularly effective in preventing damage to the protective member 41 and the optical fiber 12 placed on the protective member 41.

[0092] The optical fiber 12 can also be fixed to the protective member 41 with resin or the like. In this case, an ultraviolet-curing resin may be used as the resin.

[0093] To protect the protective member 41 and the optical fiber 12, at least a portion of the surface of the protective member 41 and the optical fiber 12 can be covered with a corrosion-resistant coating.

[0094] The material for the corrosion-resistant coating is not particularly limited, but for example, a resin with excellent corrosion resistance can be used. Examples of resins used for the corrosion-resistant coating include one or more selected from epoxy resins, polyethylene resins, etc. The corrosion-resistant coating may have multiple layers, and the material of each layer may be different or the same. (1-4) Fixing members The measuring unit 11 may have a fixing member that secures at least a portion of the optical fiber 12 within the optical fiber arrangement unit 111.

[0095] Since at least a portion of the optical fiber 12 is fixed by the fixing member 51, it is possible to prevent the optical fiber 12 from being displaced within the optical fiber arrangement section 111 after installation. Therefore, the positional accuracy when measuring strain, etc., after the optical fiber 12 has been installed can be improved.

[0096] Figures 5A and 5B show an example configuration of the optical fiber arrangement section 111 when viewed from above in the vertical direction, that is, along block arrow A in Figure 1, and when the fixing member 51 is located within the optical fiber arrangement section 111. Figure 5B is a modification of Figure 5A, so the explanation will mainly use Figure 5A.

[0097] The fixing member 51 can be placed, for example, on the surface of the slope 100. The fixing member 51 may also have a grid shape in at least a part of it, as shown in Figure 5A. That is, when the optical fiber arrangement section 111 is viewed from above in the vertical direction of the optical fiber arrangement section 111, the fixing member 51 may have a grid shape in at least a part of it.

[0098] Note that the grid shape is not limited to the rectangular grid shape shown in Figure 5A, but may also be a rhombus, polygon, or other shape.

[0099] If the fixing member 51 has a grid shape, the number of points of contact between the fixing member 51 and the optical fiber 12 can be increased, making it easier to fix the optical fiber 12 to the fixing member 51.

[0100] Mortar or concrete can be sprayed onto the slope 100 and the optical fiber arrangement section 111, and the area can be covered with a concrete structure. If the fixing member 51 has a grid shape, the fixing member 51 can also support the concrete structure.

[0101] As shown in Figure 5B, the fixing member 51 may be a rock bolt or the like installed on the slope 100 so as to intersect with the slope 100. For example, as shown in Figure 5B, if the optical fiber 12 has multiple folded portions 120, the fixing member 51, which is a rock bolt, may be placed on the folded portions 120.

[0102] By fixing the folded portion 120 with a fixing member 51 such as a rock bolt, the reaction force with respect to the shape of the ground on the slope 100 can be taken, and the sensitivity of measuring strain and other factors can be improved.

[0103] The material of the fixing member 51 is not particularly limited, but for example, metal may be used. Examples of metals include steel, stainless steel, aluminum, and aluminum alloys. (2) Scattered light measuring device The measurement unit 11 of this embodiment may further include a scattered light measuring device 112 connected to the optical fiber 12.

[0104] The measurement unit 11 has a scattered light measuring device 112 connected to the optical fiber 12, which allows for easy measurement of strain and other parameters along the longitudinal direction of the optical fiber 12. The scattered light measuring device 112 does not need to be constantly connected to the optical fiber 12; it may be detachable and connected only during measurement.

[0105] If the measurement unit 11 has multiple optical fibers 12, the scattered light measuring device 112 may have a switching device that switches the optical fiber emitting and irradiating scattered light so that the optical fiber 12 to be measured can be switched.

[0106] The measuring unit 11 may perform measurements multiple times at predetermined intervals. The predetermined intervals are not particularly limited, but for example, measurements may be performed at predetermined fixed intervals, or measurements may be performed at specific times such as in the morning and at night within a specific period such as a day, a month, or a year.

[0107] The method for measuring strain and other parameters using the scattered light measuring device 112 will be explained in the measurement method section. (3) Calculation section The measuring device 10 of this embodiment may further include a calculation unit 13.

[0108] The optical fiber placement section 111 may be arranged, for example, along the surface of the slope 100. The measurement section 11 may calculate measured values ​​including one or more selected from strain, temperature, and vibration on the slope 100 from the measurement results obtained by the measurement section 11.

[0109] Since the measuring device 10 has a calculation unit 13, strain and other factors over a wide area within the slope 100 measured by the measuring unit 11 can be easily calculated.

[0110] If the measurement unit 11 performs measurements multiple times at predetermined intervals, the calculation unit 13 may calculate the change over time of measured values ​​such as strain on the slope 100.

[0111] The measurement unit 11 performs multiple measurements, and the calculation unit 13 calculates the change in measured values ​​such as strain over time. This makes it possible to evaluate the changes in the condition of the slope 100, or, if a concrete structure is provided on the slope 100, the concrete structure, from the measured values.

[0112] The calculation unit 13 may include a CPU, which is an arithmetic processing unit for performing necessary calculations, RAM or ROM, which are main memory devices, auxiliary storage devices, input / output interfaces, and display devices, which are output devices. The CPU, main memory, auxiliary storage devices, input / output interfaces, and output devices of the calculation unit 13 can be interconnected by a bus. All of the above components of the calculation unit 13 do not need to be housed in the same enclosure; for example, the auxiliary storage device and display device may be provided externally. The auxiliary storage device is a storage device such as an SSD or HDD.

[0113] CPU stands for Central Processing Unit, RAM stands for Random Access Memory, and ROM stands for Read Only Memory. SSD stands for Solid State Drive, and HDD stands for Hard Disk Drive.

[0114] Input / output interfaces include wired or wireless interfaces for exchanging measurement data. Examples of input / output interfaces include interfaces for exchanging measurement data with the scattered light measuring device 112 of the measurement unit 11, and interfaces for controlling the alarm unit 14. Furthermore, for example, when receiving calculated measurement values ​​at a remote location, the input / output interface may include a communication port for transmitting measurement values ​​to the remote location via a network.

[0115] Furthermore, input / output interfaces may include user interfaces such as a touch panel, keyboard, and operation buttons for selecting data to be calculated by the calculation unit 13.

[0116] The main memory and auxiliary memory can also store programs for calculating strain and other parameters from the measurement data measured by the measurement unit 11. Furthermore, the main memory and auxiliary memory can store data on strain and other parameters calculated by the calculation unit 13, and can be used to calculate changes in strain and other parameters over time.

[0117] The calculation unit 13 may be formed by, for example, a personal computer (PC). Therefore, each part of the calculation unit 13 may be executed collaboratively by software and hardware in an information processing device such as a personal computer, by having the CPU execute a program that has been stored in advance. (4) Alarm section The measuring device 10 of this embodiment may further include an alarm unit 14. The alarm unit 14 can issue an alarm when the change in the time-dependent values ​​of measured values ​​such as the strain of the slope 100, calculated by the calculation unit 13, exceeds a specified value.

[0118] The measuring device 10 of this embodiment has an alarm unit 14, which makes it possible to quickly notify the operator or manager if a problem occurs in the condition of the slope 100.

[0119] The alarm unit 14 may have, for example, a display, lamp, buzzer, etc., to issue an alarm so that an operator or manager can recognize that a change in the condition of the slope 100 has occurred. The alarm unit 14 may be located, for example, within the calculation unit 13 and function as the display of the calculation unit 13. (5) Recording unit, first position identification unit, second position identification unit As shown in Figure 6, the measuring device 10 of this embodiment may also have a concrete structure 61 that is positioned to cover the slope 100 and the optical fiber arrangement section 111. Figure 6 corresponds to a cross-sectional view along line BB in Figure 1 when the measuring device 10 has a concrete structure 61. Alternatively, the optical fiber arrangement section 111 can be covered with plants or soil instead of the concrete structure 61.

[0120] The concrete structure 61 can be manufactured by spraying mortar or concrete onto the slope 100 or the optical fiber placement area 111, and allowing the mortar or concrete to harden.

[0121] If the optical fiber arrangement section 111 is covered by a concrete structure 61 or the like, the optical fiber 12 will not be visible from the outside due to the concrete structure 61.

[0122] Therefore, the measuring device 10 of this embodiment may have a recording unit 15 that records positional information of the optical fibers 12 within the optical fiber arrangement section 111 on the slope 100.

[0123] The measuring device 10 of this embodiment may further include a first position identification unit 16 that identifies the position where the measured value of the slope is obtained, calculated by the calculation unit 13 based on the position information of the optical fiber held by the recording unit 15.

[0124] The recording unit 15 records the position information of the optical fiber 12 on the slope 100, and by allowing the calculation unit 13 to identify the location where the measured value of the slope 100 was obtained based on the position information of the optical fiber 12, the condition evaluation of the slope 100 can be performed with particular accuracy.

[0125] As explained using Figure 3, the optical fiber 12 may also have bends 31 along its length at regular intervals.

[0126] Therefore, the measuring device 10 of this embodiment may also have a second position identification unit 17. The second position identification unit 17 can identify the position of the bent portion 31 in the measurement data measured by the measuring unit 11 and identify the position where the measurement value of the slope 100 calculated by the calculation unit 13 was obtained.

[0127] Since the optical fiber 12 has bends 31 along its length at regular intervals, the strain originating from the bends 31 is reflected in the measurement data. Therefore, the position of the bends 31 along the length of the optical fiber 12 can be identified in the measurement data measured by the measurement unit 11. Then, by making it possible to identify the position where the measurement value of the slope calculated by the calculation unit 13 was obtained based on the identified position of the bends 31, the condition evaluation of the slope can be performed with particular accuracy.

[0128] The measuring device 10 of this embodiment may have only one of the first positioning unit 16 and the second positioning unit 17, or it may have both the first positioning unit 16 and the second positioning unit 17. By having both the first positioning unit 16 and the second positioning unit 17, the measuring device 10 can pinpoint the position of the optical fiber 12 on the slope 100 with particular accuracy.

[0129] The recording unit 15, the first position identification unit 16, and the second position identification unit 17 may be provided individually or as an integrated device. Alternatively, the calculation unit 13, the recording unit 15, the first position identification unit 16, and the second position identification unit 17 may be integrated as a single device, either partially or entirely. For example, the recording unit 15 may be formed by an auxiliary storage device provided by the calculation unit 13, while the first position identification unit 16 and the second position identification unit 17 may be formed by a CPU, main memory, auxiliary storage device, input / output interface, output device, etc., provided by the calculation unit 13.

[0130] The recording unit 15, the first position identification unit 16, and the second position identification unit 17 may, like the calculation unit 13, have a CPU which is an arithmetic processing unit for performing necessary calculations, RAM or ROM which are main memory devices, auxiliary memory devices, input / output interfaces, display devices which are output devices, etc. Since the CPU and the like have been explained in the calculation unit 13, the explanation will be omitted here.

[0131] The recording unit 15, the first location identification unit 16, and the second location identification unit 17 may be formed by, for example, a personal computer (PC). Therefore, each part of the recording unit 15, the first location identification unit 16, and the second location identification unit 17 may be executed by the cooperation of software and hardware in an information processing device such as a personal computer, where the CPU executes a program that has been stored in advance. [2]Measurement method The measurement method of this embodiment will now be described. The measurement method of this embodiment can be carried out, for example, using a measuring device according to one aspect of this disclosure. For this reason, some of the matters described in relation to the measuring device will be omitted from the explanation. (1) Measurement process The measurement step of this embodiment may include a measurement step.

[0132] The measurement process allows the measuring device 10 to measure one or more values ​​selected from strain, temperature, and vibration on the slope 100.

[0133] The measuring device 10 may have a measuring unit 11 that includes an optical fiber arrangement unit 111 having a surface shape arranged along the surface of the slope 100, and a scattered light measuring device 112.

[0134] The measurement unit 11 has optical fibers 12 arranged within the optical fiber arrangement unit 111, and the optical fibers 12 can be connected to the scattered light measuring device 112.

[0135] The measuring unit 11 further includes a linear protective member 41 positioned within the optical fiber arrangement unit 111, wherein at least a portion of the optical fiber 12 is positioned along the longitudinal side of the protective member 41, and a portion of its surface may be covered by the protective member 41. The protective member 41 has already been described, so its description will be omitted here.

[0136] In the measurement process, scattered light is emitted from the scattered light measuring device 112 through the optical fiber 12, allowing for the measurement of strain and other values ​​along the longitudinal direction of the optical fiber 12 on the slope 100.

[0137] The measurement method of this embodiment has a measurement unit 11 that includes an optical fiber arrangement unit 111 having a surface shape, so that the optical fiber arrangement unit 111 can be installed, for example, on a slope 100 and measurements can be performed. In the measurement process, the optical fiber 12 arranged in the optical fiber arrangement unit 111 can measure one or more measurements selected from strain, temperature, and vibration along the longitudinal direction of the optical fiber 12. Therefore, the measurement method of this embodiment can measure one or more measurements selected from strain, temperature, and vibration over a wide area of ​​the entire optical fiber arrangement unit 111 in which the optical fiber 12 is arranged.

[0138] Furthermore, the measuring unit 11 has a protective member 41, and at least a portion of the optical fiber 12 is positioned along the longitudinal side of the protective member 41, so that a portion of the surface of the optical fiber 12 is covered by the protective member 41, thereby preventing damage to the optical fiber 12.

[0139] This section describes the method for measuring strain and other values ​​using the optical fiber 12 during the measurement process. (Regarding strain measurement) When measuring strain in the measurement process, it is possible to measure strain at any position along the longitudinal direction of the optical fiber, or the strain distribution along the longitudinal direction of the optical fiber.

[0140] The scattered light used for measuring strain is not particularly limited, but for example, one or more types selected from Brillouin scattered light, Rayleigh scattered light, and Raman scattered light may be used.

[0141] The strain measurement method is not particularly limited, but examples include one or more selected from BOCDA (Brillouin Optical Correlation Domain Analysis), BOTDR (Brillouin Optical Time Domain Reflectometry), FBG (Fiber Bragg Grating), BOTDA (Brillouin Optical Time Domain Analysis), BOCDR (Brillouin Optical Correlation Domain Reflectometry), etc.

[0142] The number of optical fibers used when measuring strain in the measurement process can be selected according to the measurement method. For example, when the measurement method is BOCDA or BOTDA, the number of optical fibers should be an even number of two or more, while when the measurement method is BOTDR, FBG, or BOCDR, the number of optical fibers may be one or more. (Regarding temperature measurement) When measuring temperature during the measurement process, it is possible to measure the temperature at any point along the length of the optical fiber, or the temperature distribution along the length of the optical fiber.

[0143] The scattered light used for temperature measurement is not particularly limited, but for example, one or more types selected from Brillouin scattered light, Rayleigh scattered light, and Raman scattered light may be used.

[0144] The temperature measurement method is not particularly limited, but examples include one or more selected from BOCDA, BOTDR, FBG, BOTDA, BOCDR, ROTDR (Raman Optical Time Domain Reflectmeter), etc.

[0145] The number of optical fibers used when measuring temperature in the measurement process can be selected according to the measurement method. For example, when the measurement method is BOCDA or BOTDA, the number of optical fibers should be an even number of two or more, while when the measurement method is BOTDR, FBG, BOCDR, or ROTDR, the number of optical fibers may be one or more. (Regarding vibration measurement) When measuring vibrations during the measurement process, DAS (Distributed Acoustic Sensing) can be performed using the optical fiber 12. During the measurement process, vibrations around the optical fiber 12 and the vibration distribution can be measured.

[0146] The scattered light used for measuring vibrations is not particularly limited, but for example, Rayleigh scattered light may be used. (2) Judgment process The measurement method of this embodiment may also include a determination step in which a determination is made regarding the condition of the slope 100 and the concrete structure 61 covering the slope 100 and the optical fiber arrangement section 111, based on the measured values ​​taken in the measurement step.

[0147] An example of the configuration of the judgment process is described below. (2-1) First example configuration In the first configuration example, the measurement method may further include a first determination step.

[0148] As shown in Figure 6, the slope 100 and the optical fiber arrangement section 111 may be covered by a concrete structure 61.

[0149] In this case, the measurement process allows for multiple measurements along the longitudinal direction of the optical fiber 12 on the slope 100 at predetermined intervals. The number of optical fibers 12 used for measurement is not particularly limited; for example, one optical fiber 12 may be used for measurement. Alternatively, multiple optical fibers 12 may be used for measurement. Furthermore, the measurement interval is not particularly limited and can be selected according to the slope angle of the slope, the surrounding environment, etc.

[0150] Then, in the first determination step, the presence or absence of deformation in the concrete structure 61 can be determined from the change over time of the measured values ​​along the longitudinal direction of the optical fiber 12, which were measured in the measurement step.

[0151] When the concrete structure 61 deforms, it affects the time-dependent changes in measurements along the longitudinal direction of the optical fiber 12, such as strain and temperature distribution. Therefore, by measuring the time-dependent changes in the distribution of measured values ​​such as strain and temperature along the longitudinal direction of the optical fiber 12, it is possible to determine whether or not the concrete structure 61 has deformed. (2-2) Second example configuration In the second configuration example, the measurement method may further include a second determination step.

[0152] The measurement unit 11 may have at least two optical fibers 12 arranged in parallel within the optical fiber arrangement unit 111.

[0153] Specifically, for example, as shown in Figure 4C, the measuring device 10 further includes a stranded wire 44 which is a protective member 41, and the first optical fiber 121 and the second optical fiber 122 may be arranged in the twist grooves 45 of the stranded wire 44. The arrangement of the first optical fiber 121 and the second optical fiber 122 in the stranded wire 44 is not particularly limited, and they may be arranged in the same twist groove 45 or in different twist grooves 45. For example, as shown in Figure 4C, the first optical fiber 121 and the second optical fiber 122 may be arranged in twist grooves 45 at opposing positions in a cross section perpendicular to the longitudinal side of the stranded wire 44.

[0154] Furthermore, as shown in Figure 6, the slope 100 and the optical fiber arrangement section 111 may be covered by a concrete structure 61.

[0155] In this case, the measurement process can measure the strain along the longitudinal direction of the optical fibers 12 using at least two optical fibers 12 arranged in parallel.

[0156] In the second determination step, if the difference in strain measured using at least two parallel optical fibers 12 is greater than or equal to a predetermined value, it can be determined that deformation has occurred in the concrete structure 61. In the second determination step, if the difference in strain measured using at least two parallel optical fibers 12 is less than a predetermined value, it can be determined that no deformation has occurred in the concrete structure 61 and that it is normal.

[0157] The strain and strain distribution measured using at least two parallel-arranged optical fibers 12 will be almost the same unless a large external force is applied to the optical fibers 12 causing deformation. Therefore, if the difference in strain and strain distribution measured using at least two parallel-arranged optical fibers 12 is large, it means that the optical fibers 12 are significantly bent. Thus, if the difference in strain and strain distribution measured using at least two optical fibers 12 becomes large, it can be determined that deformation has occurred in, for example, the concrete structure 61 installed to cover the slope 100. (2-3) Third example of configuration In the third configuration example, the measurement method may further include a third determination step.

[0158] As shown in Figure 6, the slope 100 and the optical fiber arrangement section 111 may be covered by a concrete structure 61.

[0159] In this case, the measurement process can use an optical fiber to measure the vibration along the longitudinal direction of the optical fiber 12 on the slope 100.

[0160] Then, in the third determination step, the presence or absence of a cavity between the concrete structure 61 and the slope 100 can be determined from the vibration distribution along the longitudinal direction of the optical fiber 12 measured in the measurement step.

[0161] When water seeps into a slope 100 covered with a concrete structure 61 due to rain or other factors, soil can be washed away, potentially creating voids between the concrete structure 61 and the soil. When voids form, the vibration pattern changes, and by measuring the vibration distribution along the length of the optical fiber 12, it is possible to determine whether or not there are voids between the concrete structure 61 and the slope 100. (2-4) Fourth example configuration In the fourth configuration example, the measurement method may further include a fourth determination step.

[0162] As shown in Figure 6, the slope 100 and the optical fiber arrangement section 111 may be covered by a concrete structure 61.

[0163] In this case, the measurement process allows for the temperature along the longitudinal direction of the optical fiber 12 on the slope 100 to be measured multiple times at predetermined intervals, i.e., at predetermined intervals. The measurement interval is not particularly limited and can be selected according to the slope angle and surrounding environment.

[0164] Then, in the fourth determination step, the presence or absence of a cavity between the concrete structure 61 and the slope 100 can be determined from the change in temperature over time along the longitudinal direction of the optical fiber 12, which was measured in the measurement step.

[0165] The slope 100 covered with the concrete structure 61 may experience soil erosion due to water infiltration caused by rain, etc., potentially creating voids between the concrete structure 61 and the soil. Since the presence of these voids affects the temperature distribution over time, the presence or absence of voids between the concrete structure 61 and the slope 100 can be determined by measuring the change in temperature distribution over time along the longitudinal direction of the optical fiber 12.

[0166] The measurement method of this embodiment may further include any optional steps. (3) Correction process The measurement method of this embodiment may further include a correction step.

[0167] In the correction process, the strain measured in the measurement process can be corrected using the temperature also measured in the measurement process.

[0168] In the correction process, the corrected strain can be calculated using, for example, the following equation (1).

[0169] (Corrected strain (%)) = (Measured strain (%)) - (Measured temperature (°C)) × (Temperature coefficient (% / °C)) ... (1) In equation (1), the "measured temperature" can be replaced with the temperature change from a reference temperature.

[0170] The temperature coefficient can be calculated in advance, for example, using the same optical fiber used for measurement, based on the relationship between a known temperature and a known strain.

[0171] By performing a correction process, the measured strain and strain distribution can be corrected by temperature, allowing for particularly accurate strain measurement. [3] Method for manufacturing a measuring device The method for manufacturing the measuring device of this embodiment will now be described. According to the method for manufacturing the measuring device of this embodiment, a measuring device according to one aspect of the present disclosure can be manufactured. For this reason, some of the matters described in the measuring device and measurement method will be omitted. (1) Optical fiber placement process, fixing member installation process The manufacturing method of the measuring device of this embodiment may include an optical fiber arrangement step.

[0172] In the optical fiber placement process, optical fibers 12 are placed along the surface of the slope 100, forming an optical fiber placement section 111 with a planar shape.

[0173] According to the manufacturing method of the measuring device of this embodiment, it is possible to manufacture a measuring device having a measuring section 11 equipped with a planar optical fiber arrangement section 111 that includes optical fibers 12 arranged along the surface of the slope 100. Therefore, according to the manufacturing method of the measuring device of this embodiment, it is possible to manufacture a measuring device that can measure one or more measurements selected from strain, temperature, and vibration over a wide area of ​​the entire optical fiber arrangement section in which the optical fibers are arranged.

[0174] In the optical fiber placement process, for example, as shown in Figure 1, the optical fibers 12 can be arranged within the optical fiber placement section 111 so as to have multiple folded portions 120. Alternatively, in the optical fiber placement process, multiple optical fibers 12 may be arranged along the surface of the slope 100. In this case, if necessary, the multiple optical fibers 12 may be arranged so that at least some of them intersect with each other, as explained with reference to Figure 2.

[0175] The optical fiber 12 may be placed on the protective member 41 before being subjected to the optical fiber placement process. That is, the optical fiber placement section 111 may further have a linear protective member 41. In this case, the optical fiber 12 is arranged along the longitudinal side of the protective member 41, and a portion of its surface can be covered by the protective member 41.

[0176] The measuring unit 11 has a protective member 41, and at least a portion of the optical fiber 12 is positioned along the longitudinal side of the protective member 41, so that a portion of the surface of the optical fiber 12 is covered by the protective member 41, thereby preventing damage to the optical fiber 12.

[0177] In the optical fiber placement process, the method for placing and fixing the optical fibers 12 on the slope 100 is not particularly limited, but they may be fixed, for example, by fixing members 51 that have been pre-installed in the optical fiber placement section 111.

[0178] When the fixing member 51 is placed within the optical fiber arrangement section 111, the manufacturing method of the measuring device in this embodiment may also include a fixing member placement step in which the fixing member 51 is placed along the surface of the slope 100. In the fixing member placement step, the fixing member 51 can be placed and fixed along the surface of the slope 100. (2) Optical fiber position recording process The manufacturing method of the measuring device of this embodiment may also include an optical fiber position recording step.

[0179] The optical fiber position recording step can record the position of the optical fiber 12 in the optical fiber arrangement section 111. The position of the optical fiber 12 recorded in the optical fiber position recording step can be recorded and stored, for example, in a recording section 15 of a measuring device according to one aspect of this disclosure.

[0180] The manufacturing method of the measuring device in this embodiment includes an optical fiber position recording step, and by recording the position information of the optical fiber 12 on the slope 100, the location where measurement values ​​such as strain for the slope 100 are obtained can be easily identified. Therefore, the condition evaluation of the slope 100 can be performed with particular accuracy. (3) Concrete structure placement process The manufacturing method of the measuring device of this embodiment may also include a concrete structure placement step.

[0181] In the concrete structure placement process, mortar or concrete can be sprayed to cover the slope 100 and the optical fiber placement area 111. The sprayed mortar or concrete hardens to form a concrete structure.

[0182] By implementing the concrete structure placement process, the optical fibers 12 and the slope 100 can be protected, and the shape stability of the slope 100 can be improved. [Explanation of symbols]

[0183] 10 Measuring device 100 slope 11 Measuring part 111 Optical fiber layout section 112 Scattered light measuring device 12 Optical Fibers 120 Folded section 12A optical fiber 12B optical fiber 121 First Optical Fiber 122 Second Optical Fiber 13 Calculation Section 14 Alarm section 15 Records Section 16 First position identification part 17 Second position specifying section 31. Bending section L31 distance L40 tangent 41 Protective component 42 Groove 43 Cavity 44 stranded wire 441 strands 441A Center wire 441B Outer strand 45 twisted grooves 51 Fixing member 61 Concrete structures

Claims

1. It has a measurement section that includes an optical fiber arrangement section having a surface shape, The measuring unit comprises an optical fiber arranged within the optical fiber arrangement section and a linear protective member. A measuring device in which at least a portion of the optical fiber is arranged along the longitudinal side of the protective member and a portion of its surface is covered by the protective member.

2. The measuring device according to claim 1, wherein the optical fiber has a plurality of folded portions within the optical fiber arrangement portion.

3. The measurement unit has a plurality of optical fibers, The measuring device according to claim 1 or claim 2, wherein, when the optical fiber arrangement section is viewed from above in the vertical direction of the optical fiber arrangement section, the plurality of optical fibers are arranged such that at least a portion of them intersect with each other.

4. The protective member includes a stranded wire made by twisting together metal strands, The measuring device according to claim 1 or claim 2, wherein the optical fiber is arranged in the twist groove of the stranded wire.

5. The measuring device according to claim 1 or claim 2, wherein the measuring unit has a fixing member that fixes at least a portion of the optical fiber within the optical fiber arrangement unit.

6. The measuring device according to claim 5, wherein, when the optical fiber arrangement section is viewed from above in the vertical direction of the optical fiber arrangement section, at least a portion of the fixing member has a grid shape.

7. The measuring device according to claim 1 or claim 2, wherein the measuring unit further comprises a scattered light measuring device connected to the optical fiber.

8. The optical fiber arrangement section is arranged along the surface of the slope, The measuring device according to claim 1 or claim 2, further comprising a calculation unit that calculates a measurement value including one or more selected from strain, temperature, and vibration on the slope from the measurement results of the measurement unit.

9. The aforementioned measuring unit performs measurements multiple times at predetermined intervals. The measuring device according to claim 8, wherein the calculation unit calculates the change over time of the measured value on the slope.

10. The measuring device according to claim 9, further comprising an alarm unit that issues an alarm when the range of change over time of the measured value of the slope, calculated by the calculation unit, exceeds a specified value.

11. A recording unit that records positional information of the optical fibers within the optical fiber arrangement section on the slope, The measuring device according to claim 8, further comprising: a first position identification unit that identifies the position where the measured value of the slope is obtained, calculated by the calculation unit based on the position information of the optical fiber held by the recording unit.

12. The optical fiber has bends along its length at regular intervals. The measuring device according to claim 8, further comprising: a second position identification unit that identifies the position of the bent portion in the measurement data measured by the measuring unit, and a second position identification unit that identifies the position where the measured value of the slope calculated by the calculation unit is obtained.

13. The system includes a measurement process in which a measuring device measures one or more measurements selected from strain, temperature, and vibration on a slope. The measuring device is, The measurement unit includes an optical fiber arrangement section having a surface shape arranged along the surface of the slope, and a scattered light measuring device. The measuring unit comprises an optical fiber arranged within the optical fiber arrangement section and a linear protective member, wherein at least a portion of the optical fiber is arranged along the longitudinal side of the protective member and a portion of its surface is covered by the protective member. The optical fiber is connected to the scattered light measuring device, The measurement method involves, in the measurement step, emitting scattered light from the scattered light measuring device through the optical fiber, and measuring the measured value on the slope along the longitudinal direction of the optical fiber.

14. The aforementioned slope and the optical fiber arrangement area are covered by a concrete structure. In the measurement step, the optical fiber is used to measure the measurement value along the length of the optical fiber multiple times at predetermined intervals. The measurement method according to claim 13, further comprising a first determination step of determining whether or not deformation has occurred in the concrete structure based on the change over time of the measured value along the longitudinal direction of the optical fiber measured in the measurement step.

15. The measurement unit has at least two optical fibers arranged in parallel within the optical fiber arrangement unit, The aforementioned slope and the optical fiber arrangement area are covered by a concrete structure. In the measurement step, the strain along the longitudinal direction of the optical fiber is measured using at least two optical fibers arranged in parallel. The measurement method according to claim 13, further comprising a second determination step of determining that deformation has occurred in the concrete structure if the difference in strain measured using at least two optical fibers arranged in parallel is greater than or equal to a predetermined value.

16. The aforementioned slope and the optical fiber arrangement area are covered by a concrete structure. In the measurement step, the vibration along the longitudinal direction of the optical fiber on the slope is measured using the optical fiber. The measurement method according to claim 13, further comprising a third determination step of determining whether or not there is a cavity between the concrete structure and the slope based on the distribution of vibration along the longitudinal direction of the optical fiber measured in the measurement step.

17. The aforementioned slope and the optical fiber arrangement area are covered by a concrete structure. In the measurement step, the temperature along the length of the optical fiber on the slope is measured multiple times at predetermined intervals using the optical fiber. The measurement method according to claim 13, further comprising a fourth determination step of determining whether or not there is a cavity between the concrete structure and the slope, based on the change in temperature over time along the longitudinal direction of the optical fiber measured in the measurement step.

18. A fiber optic arrangement step involves arranging optical fibers along the surface of a slope to form an optical fiber arrangement section having a planar shape, The process includes an optical fiber position recording step for recording the position of the optical fiber in the optical fiber arrangement section, The optical fiber arrangement section further includes a linear protective member. A method for manufacturing a measuring device, wherein at least a portion of the optical fiber is arranged along the longitudinal side of the protective member, and a portion of its surface is covered by the protective member.

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