JP2000002503A - Structure member integrity monitoring sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure member integrity monitoring sensor capable of judging the integrity of structure member with a simple structure having good durability and low cost. SOLUTION: A structure member integrity monitoring sensor M1 is constituted to have a pulse signal generator 1 generating impulse type or step type pulse signal Si or Ss, conductive cables 12 and 13 buried in foundation piles 10 and a conductor 4 provided along the conductive cables 12 and 13. Also constituted of is an oscilloscope 15 judging the damage state near the damage point 12b of foundation piles 10 based on the pulse signal Si or Ss and reflection signals Sri3, Sri3' or Srs3, Srs3' output by one ends 12a and 13a of the conductive cables 12 and 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structural member soundness monitoring sensor provided for a structural member and used for judging the soundness of the structural member.

[0002]

2. Description of the Related Art As is well known, civil and architectural high-rise structures such as bridges, elevated roads, tunnels, and buildings have a long service period.
They are exposed to the problem of degradation due to harsh environments. To solve such a problem, it is effective to arrange sensors at important points of a structure or a structural member, monitor the soundness as needed, and guarantee long-term durability. Here, “as needed” means always or periodically, or immediately after receiving an earthquake or an overload.

The following is a description of the points where such monitoring is considered to be particularly effective. (A) Investigation of members and parts in places and positions where visual inspection ability cannot be exerted, for example, members with underground parts, finishing materials, ceiling materials, covers (such as rooftop waterproof layers and tunnel linings) Parts, parts that are not visible due to other equipment and equipment plumbing, places that are too small to access for work, tightly closed places, etc.

(B) Investigation of parts and parts in places and places where humans cannot easily enter, or places where danger is involved in entry or work. For example, work at high places and secure safe work platforms Places where there is a harsh place, structures that are in contact with water or sea water, underwater or underwater structures, (Ultra) high-voltage equipment such as substation facilities, nuclear power plants, radioactive waste disposal sites, etc. Facilities that handle radioactive materials such as, places with harmful gases or irritating odors, places that are prone to lack of oxygen, places with a lot of traffic vehicles, and waste that should be avoided
There are places with light, noise, vibration, dust, etc., places with high temperature and high humidity.

(C) When a new structural material or a new construction method is applied Adoption of a new structural material or a new construction method is carefully performed based on many results of prior experiments and studies. In many cases, there is no problem with long-term durability. However, civil and architectural structures have a long service period, so taking into account changes in usage conditions and environmental changes, avoiding accidents and guaranteeing long-term durability will require monitoring methods. Can be very effective. This also eliminates the need for excessive design due to the small amount of design / operation data, and at the same time, can be expected to have advantages such as significantly improved reliability.

[0006] In the case of a building structure, the design itself is not defined by the design system based on the current allowable stress design method, but also by the limit body design method and the standard, but by defining the performance itself instead of defining the structural details. They are also starting to develop a new design system that guarantees their performance. With this new design, performance (function)
Balancing safety and cost (economic) is an even more important technical issue. In such a case, the monitoring technology is considered to be one of the basic technologies for supporting a new design or securing risks.

By the way, monitoring techniques include instruments for daily inspection and diagnosis, such as building inspection of structures that have been in operation for a long time, and damage assessment after an earthquake, from daily visual inspection. There are various methods for investigating, diagnosing, and evaluating the soundness, such as carrying in and conducting experiments and actual measurements.

[0008] Of these, the monitoring technique using an instrument or the like can be broadly classified into the following (A) and (B). That is, (A) a method of arranging a sensor at the end of a cable for transmitting a signal, or a method of providing a sensor function, and (B) a method of using a cable for transmitting a signal itself as a sensor. Here, in the monitoring of a structure or a structural member, since the monitoring target is wide or multi-point,
When comparing the above (A) and (B), it is considered that (B) is more advantageous.

Considering the prior art focusing on the method (B), the techniques proposed so far as the method corresponding to (B) are as follows in view of the materials used. There are two. (B-1) Using an optical fiber (B-2) Using a conductive wire such as a carbon fiber bundle. Here are some explanations for these.

(B-1) Using Optical Fiber An optical fiber is a thin wire made of glass or plastic and can transmit light without loss even if it is slightly bent. here,
The basic structure of an optical fiber will be described below by taking a glass (glass) fiber as an example. The central part is made of quartz glass material having a diameter of several microns to 10 microns and a refractive index of na, and is called a core region. Refractive index around it
It is a double structure surrounded by a quartz glass material of another composition of nb. The outer quartz glass region is called the cladding region, and the diameter of the cladding region is about 0.1 mm.
Micron. The refractive index of the core is about 1.5, and the refractive index difference between the core and the clad is about 0.2 to 1.0% .This difference in refractive index causes the light incident on the core to repeat total reflection at the boundary between the core and the clad. The point of an optical fiber is that it propagates with extremely small propagation loss. Furthermore, since the outer periphery of the optical fiber is covered with silicon, urethane, or the like, it has elasticity and good strength. The breaking elongation of the optical fiber itself is about 1%.

As a method for monitoring the progress of cracks and cracks in fiber reinforced plastics (FRP) such as carbon fiber and glass fiber, and composite materials thereof, a coating on the outer peripheral portion of the optical fiber is removed, and the FRP or composite material thereof is removed. Embedding in it has been done. This is because the strength of the coated optical fiber is extremely high, and even if the coated optical fiber is buried as it is or attached with an adhesive, peeling occurs on the outer peripheral surface of the coating, and the optical fiber itself is not damaged. To determine whether or not there is damage, or the degree of damage, a continuity test of the optical fiber, that is, a method of measuring or visually observing the transmission of light (loss of transmitted light), or entering light from one end and turning back Weak reflected light (backscattered light) can be measured by measurement.

Further, a fault point (damaged position) generated in the optical fiber cable can be obtained by measuring a reflected pulse (Fresnel reflection) generated in the fractured surface by an optical pulse tester. However, in the case of an optical cable, a reflected pulse may not be generated depending on the state of breakage. However, even in such a case, a fault point can be searched using the above-mentioned backscattered light as a clue by the method described below. That is, the optical fiber has microscopic refractive index fluctuations due to non-uniformity of substances and densities / components smaller than a unit of wavelength, and this causes scattered light called Rayleigh scattering. A part of the scattered light distributed in the length direction becomes a waveguide mode of the optical fiber and returns to the incident end,
By measuring the level of this weak reflected light (backscattered wave), the breaking point can be evaluated. The level of backscattered light varies exponentially with propagation time.
The unit length loss can be detected from this level difference, and the break point can be detected from the disappearance of the backscattered light.

(B-2) Using a conductive wire such as a carbon fiber bundle The principle of monitoring when such a conductive wire is used is as follows. That is, for example, the carbon fiber yarn in the carbon fiber glass fiber reinforced plastics (CFGFRP) material is a conductive material in which ultrafine carbon long fibers are bundled in thousands. When a tensile load is applied to this carbon fiber material, the carbon fiber gradually starts to break due to its elongation, and at a predetermined elongation, most of the carbon fiber yarn breaks substantially, and the carbon fiber yarn sharply increases the electric resistance value. To raise. When the load is further increased, the carbon fiber yarn is completely broken, and the electric resistance becomes a very large value (almost infinite in the air). Also, when the load is removed, the deflection of the member decreases and the carbon fiber material returns to its original shape, but the broken fiber does not return to its original state, so the electrical resistance value is larger than the original state. Is shown. From this, by examining the relationship of load-elongation of the member-residual value of the electric resistance in advance, it is possible to easily estimate the load applied to the member or the elongation of the member from the residual value of the electric resistance. As such, the degree of damage (or soundness) of the member can be monitored.

[0014] Furthermore, the carbon fiber bundle is a sensor that works on the tension side. In addition, the carbon fiber bundle is required to expand its functions such as detection on the compression side and crack detection of concrete members and to improve sensitivity and accuracy. Conductive wire (or material)
There has been proposed a sensor using the same. For example, a sensor using a new conductive wire (or material) includes: (i) a narrow, longitudinally stretched (strip-shaped) foil covered with highly insulating plastics (derivative material); Material (conductive metal foil). (Ii) Reinforced plastics (RP) comprising a reinforcing agent for carbon fiber (CF) and an epoxy resin, which is processed into a rod shape by a drawing method (CFRP). (Iii) a reinforcing material of a fiber bundle in which carbon fiber (CF) and glass fiber (GF) are bundled, epoxy,
A molded article (CFGFRP) of reinforced plastics (RP) comprising a resin such as vinyl ester. Various cross-sectional shapes such as a bar, a rectangle, a sheet, and a net can be considered. Further, the glass fiber can be replaced with a ceramic fiber, an aramid fiber, or a cellulose resin. (Iv) A molded article of highly conductive plastics obtained by dispersing and curing a conductive powder. here,
Examples of the conductive powder include carbon (carbon black and graphite) powder and ceramic powder such as titanium carbide and titanium nitride. (V) A highly conductive mortar formed by dispersing and curing a conductive powder. Here, the conductive powder is the same as (iv). (Vi) Highly conductive plastics formed bodies or mortar formed bodies obtained by dispersing and curing short fibers (for example, short fibers of carbon fibers) having conductive powder are proposed.

[0015]

As described above, the conventional monitoring device for structural members using an optical fiber has an advantage that the site of damage can be specified. When considering application to objects or structural members, the following (1) to (7)
There are problems as described in

(1) The material of the coated optical fiber is glass, but glass has a weak point that it is weak to alkalinity of concrete. Therefore, there is a problem in using the coated optical fiber in the concrete body as a sensor for long-term monitoring.

(2) Since the coated optical fiber has a high strength, if the coated optical fiber is applied as it is to a structural member, the damaged portion of the optical fiber may not match the damaged portion of the structural member, There is a concern that peeling may occur between the substrate and the structural member, which may cause a decrease in measurement accuracy.

(3) When the coated optical fiber is used as a mere optical signal transmission cable, since the elongation at break of the optical fiber is only about 1%, reinforcement of a carbon fiber sheet or the like with high elasticity and small elongation at break is used. Except for the case where the optical fiber is arranged in the material, it is necessary to cure the optical fiber by a protective tube or the like.

(4) Since the mouth of the optical fiber itself is the incident end face, a portion between the incident end face and a predetermined point is a so-called dead zone where measurement is impossible. Therefore, there is a problem in that when a fault point exists in the dead doan, the fault point cannot be detected. The distance of the dead zone varies depending on the wavelength of light and the measurement accuracy of the instrument, but is usually 8 m for a single mode optical fiber and 3 m for a multimode optical fiber. Furthermore, the distance of this dead zone can be as large as 10 to 20 m when a specific measuring method is used.

(5) If the strain or deformation of the core material of the optical fiber due to the tensile load or the like is within the elastic range, the optical fiber returns to the state before the tensile load was applied when the tensile load was removed. Therefore, even if the measurement is performed in a state where the tensile load has been removed, it is not possible to know a past state in which the tensile load has been applied. (In the case of carbon fiber, even for strain and deformation before tensile (rupture) elongation,
When a part of the filament is cut, it is possible to predict the maximum strain and the maximum deformation by measuring the electric resistance value later. )

(6) It is not appropriate to give the optical fiber a bend having a small curvature from the viewpoint of strain measurement and light loss. For this reason, it is difficult to perform wiring with sudden bending. (7) The results need to be corrected for the temperature dependence of the optical fiber.

On the other hand, in a monitoring device for a structural member using a conventional conductive wire (a carbon fiber bundle or a new conductive wire in place of the carbon fiber bundle), a change in the resistance value of the conductive wire causes any one of the structural members to change. Although it can be confirmed that damage has occurred at the position, it has been difficult to specify at which position on the conductive wire the damage has occurred. In addition, the conductive wire is divided into several ranges, and a plurality of terminals are provided not only at both ends but also at an intermediate point,
It has also been proposed to determine the range of the damaged part by measuring the resistance value between them, but in this case, a plurality of signal cables connecting between a plurality of terminals and a measuring device are used. It is necessary, and further consideration is necessary in practical use in consideration of cost, difficulty of construction, and the like.

The present invention has been made in view of the above problems, has excellent durability, is low in cost, has a simple structure, and has not only the presence or absence of damage in a structural member, but also It is an object of the present invention to provide a structural member soundness monitoring sensor capable of easily ascertaining a damaged position and a damaged state.

[0024]

Means for Solving the Problems To solve the above problems, the present invention employs the following means. That is,
The structural member health monitoring sensor according to claim 1, wherein the conductive wire disposed inside or on the surface of the structural member, and a conductive conductor disposed close to and along the conductive wire, A pulse signal supply unit configured to supply a pulse signal to one end of the conductive wire; and a damage position of the structural member, the damage position of the structural member being identified based on the pulse signal and a reflection signal output from one end of the conductive wire. And a determination means for determining a state.

According to a second aspect of the present invention, there is provided the structural member health monitoring sensor according to the first aspect, wherein the structural member has at least one pair of the conductive wires extending in the same direction. And the pulse signal supply means is configured to supply the pulse signal from at least one end of at least one of the pair of conductive wires, wherein the determination means Damage to the structural member based on the pulse signal, a first reflection signal output from one end of the conductor, and a second reflection signal output from the other end of the conductor. It is characterized in that the position is specified and the damaged state of the structural member is determined.

According to a third aspect of the present invention, the structural member health monitoring sensor is the structural member health monitoring sensor according to the first or second aspect.
The structure is such that a damaged position of the structural member is specified based on the pulse signal, a reflection signal output from one end of the conductor, and a transmission signal output from the other end of the conductor. .

The structural member soundness monitoring sensor according to the first to third aspects of the present invention is a so-called TDR.
(Time Domain Reflectmetry) This is for applying the measurement method to the determination of the soundness of a structure. Here T
In the DR measurement method, an impulse-like or step-like pulse signal is input to a conductive DUT, and this pulse signal (incident wave) is superimposed on a reflected signal (reflected wave) reflected by the DUT. A method of measuring impedance characteristics and impedance discontinuity of a device under test as a function of distance based on the waveform of the reflected signal thus obtained.

The above-described soundness monitoring sensor for a structural member can be obtained by embedding a conductive wire in the structural member in advance or laying a conductive wire on the surface of the structural member and inputting a pulse signal to the conductive wire. It is possible to measure the impedance at each position on the wire, and when any structural member is damaged, the impedance of the conductor changes near the damaged position. Thereby, the damage state of each part of the structural member can be monitored.

In this case, if a conductor having a smaller mechanical strength (elongation at break) than the conductor is arranged close to the conductor, the impedance of the conductor may be affected by the conductor. If the conductor breaks, cracks (cracks), or separates due to structural member damage, the impedance around the conductor changes, and this change is detected by TDR measurement on the conductor. You. Furthermore, when not only the conductor but also the conductor itself is damaged, a change in impedance that combines the damage to the conductor itself and the damage to the conductor is detected by TDR measurement of the conductor.

In this case, the conductor arranged along the conductor amplifies the degree of impedance change of the conductor,
This serves to enable highly accurate measurement. That is, as shown in FIG.
00, concrete C near the surface 100a
Suppose that the conductor 102 is embedded in the inside, and the conductor 103 is further arranged along the conductor 102. In this case, assuming that a crack 105 is generated so as to penetrate through the concrete C and the conductor 103 and that the conductor 102 is not damaged by the crack 105, the conductor 105 extends in the longitudinal direction (p direction in the drawing) of the conductor 102. The change in the electrical characteristics around the conductor 102 as seen is as shown in FIG.
5 across conductor 103 → air (crack 105)
→ It is determined by the conductor 103.

On the other hand, as shown in FIG. 11B, when only the conductor 102 is buried near the surface of the structural member 100 (when the conductor 103 is not provided), the conductor 102
As shown in FIG. 12 (b), the change in the electrical characteristics around the conductor 102 as seen in the longitudinal direction (p direction in the figure) of concrete C → air (crack 105) → concrete C Will be defined by

When comparing the cases shown in FIGS. 12 (a) and 12 (b), the electrical characteristics of the air portion remain the same in both cases. The degree of change in impedance with respect to
2, the degree of change in impedance along conductor 10
3 is larger. Accordingly, by arranging the conductor 103 along the conductor 102, cracks can be easily detected as compared with a case where the conductor 103 is not arranged, and more accurate measurement can be performed.

The effect of arranging the conductor 103 becomes even more remarkable when water (groundwater) enters the crack 105. That is, since water (groundwater) conducts electricity much better than air, when water (groundwater) enters the crack 105 in the situation shown in FIGS. Is small compared to the case where there is no intrusion of water. However, if the conductor 103 is arranged, the change in impedance is amplified by the action described above. This makes it possible to easily detect the presence or absence of cracks.

The above description is an example in the case where the mechanical strength such as the elongation at break of the conductor is smaller than the mechanical strength of the conductor. In the opposite case, that is, when the mechanical strength of the conductor is smaller than that of the conductor. If it is stronger than that, when both the conductor and the conductor are damaged, the combined impedance change will be detected by the TDR measurement of the conductor, and the impedance change will be amplified as in the above example. Operation is obtained, but when the conductor is not damaged and only the conductor is damaged, only the change in impedance of the conductor is detected, and the measurement accuracy in this case is the same as when no conductor is arranged Become.

According to a fourth aspect of the present invention, there is provided a health monitoring sensor for a structural member having a conductive wire disposed inside or on the surface of the structural member, and having a conductive property arranged closely along the conductive wire. A conductor, a high-frequency signal supply unit for inputting a high-frequency signal to one end of the conductor, a high-frequency signal supply unit, and a damaged position of the structural member based on a reflected signal output from one end of the conductor; And a judging means for judging a damage state of the structural member.

According to a fifth aspect of the present invention, there is provided the structural member health monitoring sensor according to the fourth aspect, wherein at least one pair of the conductive wires extends in the same direction. And the high-frequency signal supply means is configured to supply the high-frequency signal from at least one end of at least one of the pair of conductive wires, and the determination means Damage to the structural member based on the high-frequency signal, a first reflection signal output from one end of the conductor, and a second reflection signal output from the other end of the conductor. It is characterized in that the position is specified and the damaged state of the structural member is determined.

A structural member health monitoring sensor according to claim 6 is the structural member soundness monitoring sensor according to claim 4 or 5, wherein the determining means comprises:
The damage position of the structural member is specified based on the high-frequency signal, a reflection signal output from one end of the conductor, and a transmission signal output from the other end of the conductor. .

The structural member soundness monitoring sensor according to the fourth to sixth aspects of the present invention is a so-called vector network analyzer.
r; VNA) to determine the soundness of the structure. A VNA is a device that outputs an arbitrary sine wave signal and measures the phase characteristics and amplitude of an incident wave to the device under test and a reflected wave from the device under test. By using the port of
The transmission characteristics can be examined with respect to transmission line loss, propagation delay time, and the like. Here, a conductor buried in the structural member or laid on the surface of the structural member,
By inputting a high-frequency signal, while examining the phase characteristics and the amplitude characteristics in the frequency domain of the reflected wave and the like obtained from the conducting wire, based on these information, in the determination means, for example, using means such as inverse Fourier transform, A waveform on the time axis is obtained for the reflected wave, and thereby, a change in impedance along each part of the conductor is examined.

In this case, if a conductor having a smaller mechanical strength (elongation at break) than the conductor is arranged close to the conductor, the impedance of the conductor may be affected by the conductor. If the conductor breaks, cracks (crack), or separates due to structural member damage, the impedance around the conductor changes, and this change is detected by VNA measurement on the conductor. You. Furthermore, when not only the conductor but also the conductor itself is damaged, a change in impedance that combines the damage to the conductor itself and the damage to the conductor is detected by VNA measurement of the conductor.

Further, in this case, similarly to the above-described inventions according to the first to third aspects, the conductor arranged along the conductor amplifies the degree of change in the impedance of the conductor, thereby achieving highly accurate measurement. It works to make it possible.

According to a seventh aspect of the present invention, there is provided a health monitoring sensor for a structural member according to any one of the first to sixth aspects, wherein a stress of a predetermined value or more acts on the conductor. Then, at least two terminals are connected to the conductor, and resistance measuring means for measuring a resistance value between these terminals is connected to the conductor. It is characterized by being.

With the above structure, the structural member soundness monitoring sensor may damage the structural member in addition to determining the soundness of the structural member using a pulse signal or a high frequency signal. By using the fact that a stress acts on the conductor when the conductor is applied and the resistance value of the conductor changes due to the stress, the soundness of the structural member can be monitored by observing the resistance value of the conductor.

The structural member health monitoring sensor according to claim 8 is the structural member health monitoring sensor according to any one of claims 1 to 7, wherein the breaking elongation of the conductor is equal to the breaking of the conductor. It is characterized by being smaller than the elongation. With such a configuration, in the health monitoring sensor for the structural member, when the structural member is damaged and cracks or the like occur, the conductor is damaged before the conductive wire, and accordingly, the conductor is damaged. This will change the impedance around the conductor. Thereby, unlike the case where only the conductor is simply provided in the structural member, minute cracks or the like that do not change the electrical characteristics of the conductor at all can be detected satisfactorily.

[0044]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a structural member health monitoring sensor M of the present invention. This structural member health monitoring sensor M
This is for applying the measurement method using TDR as described above to the determination of the soundness of a structural member. Hereinafter, the basic configuration and measurement principle will be described.

In FIG. 1, reference numeral 1 denotes a pulse signal generator, 2 denotes a conductive wire, 3 denotes an oscilloscope, and 4 denotes a conductor arranged along the conductive wire 2. The pulse signal generator 1 receives the pulse signal Si shown in FIG.
The step-like pulse signal Ss shown in (d) can be generated. Further, a probe (not shown) is connected to the pulse signal generator 1, and these pulse signals S
i or the pulse signal Ss is output via the probe. Further, when the pulse signal generator 1 and the oscilloscope 3 are viewed from the tip of the probe, the characteristic impedance is Zo (50Ω or 75Ω).

On the other hand, the conductive wire 2
The pulse signal Si or the pulse signal Ss is input to one end 2a of the bundle through a probe. The length and diameter of the conductive wire 2 and the resistivity of the material are designed so that the impedance and the characteristic impedance Zo match as much as possible so that no reflection occurs at the one end 2a.

The outer peripheral surface of the conductive wire 2 is covered with a covering material (not shown) made of plastics. As this covering material, a material whose breaking elongation is equal to or smaller than that of a stranded wire or a central conductor described later is used. Here, when a copper wire is used as the conductive wire 2 (stranded wire), it is desirable to use a plastic coating whose tensile (rupture) elongation by a tensile load is several percent or less. As a result, as the cracks and cracks in the concrete member progress, the plastics as the coating material crack or crack in the same way, and the impedance around the coating material and the surrounding material changes. The situation can be monitored with higher sensitivity.

Examples of the plastics having a tensile (rupture) elongation of several percent or less include a standard grade of polystyrene and a standard grade of vinyl ester epoxy resin. Here, the tensile (rupture) elongation of a standard grade of polystyrene is 2%,
On the other hand, the tensile (rupture) of the standard grade vinyl ester epoxy resin is 3%.

The oscilloscope 3 outputs the reflected signal Sr
i3 (see FIG. 2C) or a reflected signal Srs3 (see FIG. 2C).
(See (d)). Further, the oscilloscope 3 has a built-in CPU (Central Processing Unit) (not shown) for performing various calculations.

The conductor 4 is formed of, for example, a carbon fiber bundle in which long carbon fibers are bundled, so that when a tensile load is applied, the electric resistance value changes. Have been. Further, the conductor 4 has
Terminals 5 and 5 are provided at both ends, and these terminals 5 and 5 are connected to these terminals 5 and 5
It is connected to a tester 7 for measuring the DC resistance or impedance between them.

In the above configuration, it is assumed that a damaged portion due to a tensile load or the like, that is, a failure point 2b is present at an intermediate portion of the conductive wire 2 shown in FIG. As a result, in the conductive wire 2, an impedance mismatch occurs due to the failure point 2b. Since the elongation at break of the conductor 4 is smaller than that of the conductive wire 2, the conductor 4 near the fault point 2b of the conductive wire 2 is also damaged, but in FIG. Omitted.

In this state, a pulse signal Si (see FIG. 2C) is applied from the pulse signal generator 1 shown in FIG. 2B to the one end 2a of the conductive wire 2 shown in FIG. 2A. The pulse signal Si propagates through the conductive wire 2 when output through the conductive wire 2. Then, part of the pulse signal Si is
Reflected by the fault point 2b, the reflected signal Sri1 is
The light propagates toward one end 2a. On the other hand, the rest of the pulse signal Si is reflected by the other end 2c and propagates as a reflected signal Sri2 toward the one end 2a.

Thus, from one end 2a of the conductive wire 2, a reflection signal Sri3 in which the above-mentioned reflection signal Sri1 and reflection signal Sri2 are superimposed is output. This reflected signal Sri3 is input to the oscilloscope 3, and as a result, the waveform of the reflected signal Sri3 shown in FIG. In this figure, part A
Is a portion corresponding to the reflection signal Sri1, and the portion B
Is a portion corresponding to the reflection signal Sri2.

Accordingly, in FIG. 2C, the time between the pulse signal Si and the portion A is obtained, and the time between the pulse signal Si and the portion A is obtained.
The result of multiplying the propagation speed of ri3 (≒ light speed c) is "2"
The distance from one end 2a to the fault point 2b shown in FIG. That is, the position of the fault point 2b on the conductive wire 2 is specified.

Further, a pulse signal Ss (see FIG. 2D) having a step shape is probed from the pulse signal generator 1 shown in FIG. 2B to one end 2a of the conductive wire 2 shown in FIG. 2A. , A part of the pulse signal Ss becomes
Reflected by the fault point 2b, as a reflected signal Srs1,
The light propagates toward one end 2a. On the other hand, the rest of the pulse signal Ss is reflected by the other end 2c and propagates as a reflected signal Srs2 toward the one end 2a.

Thus, from one end 2a of the conductive wire 2, a reflection signal Srs3 in which the above-mentioned reflection signal Srs1 and reflection signal Srs2 are superimposed is output. Then, the reflection signal Srs3 is input to the oscilloscope 3. As a result, the oscilloscope 3 displays the waveform of the reflected signal Srs3 shown in FIG. In this figure, a part C is a part corresponding to the reflection signal Srs1, and a part D is a part corresponding to the reflection signal Srs2.

Therefore, in FIG. 2D, the time between the rise of the pulse signal Ss and the portion C is obtained, and the result obtained by multiplying the time by the propagation speed of the reflected signal Srs3 (≒ light speed c) is “2”. The distance from one end 2a to the fault point 2b shown in FIG. That is, the position of the fault point 2b on the conductive wire 2 is specified.

At this time, the conductor 4 is connected to the conductive wire 2
By being damaged at a lower strength (elongation at break), it plays a role of amplifying a change in impedance in the longitudinal direction around the conductive wire 2. When a tensile or compressive load is applied to the conductor 4 due to cracks or the like generated in the structural member, the resistance between the terminals 5 and 5 changes. By observing the value, it is possible to monitor that any stress is acting on the conductor 4. Therefore, the fault point 2b in the conductive wire 2 due to the pulse signal
In addition to the discovery and identification of the above, by monitoring the resistance value of the conductor 4, simple monitoring can be performed, and the monitoring accuracy can be further improved.

In the above description, an example in which both the conductive wire 2 and the conductor 4 are damaged has been described. Instead, the conductive wire 2 has no damaged portion, and Even when only the conductor 4 having a small elongation is damaged, the impedance of the conductive wire 2 is mismatched near the damaged portion due to the damage of the conductor 4. , And can be handled in the same manner as in the above description.

The above is the basic configuration of the soundness monitoring sensor M of the structural member when the TDR measuring method is applied. When the VNA measuring method is used for monitoring the structural member, the above-described pulse signal is used. Instead of the generator 1 and the oscilloscope 3, a vector network analyzer (not shown) may be used. Then, an arbitrary sine wave signal is input to the conductive wire 2 from the vector network analyzer, and the phase characteristics and the amplitude characteristics of the sine wave signal and the reflected wave obtained from the conductive wire 2 are measured. By examining the transfer characteristics with respect to the transmission path loss, propagation delay time, and the like, it is possible to estimate the position and the like of the fault point 2 b occurring in the conductive wire 2.

Next, examples in which the TDR measurement method is applied to an actual structure will be described as first and second embodiments. [First Embodiment] FIG. 3 shows a structural member health monitoring sensor M according to the present embodiment.
It is a figure which shows the example at the time of applying ₁ to the foundation pile 10 made of a reinforced concrete. Among them, FIG.
A sectional elevation view showing a health monitoring sensor M ₁ of the foundation pile 10 and the structural member, (b) shows a sectional plan view of a foundation pile 10. 3 (a) and 3 (b)
In FIGS. 1 and 2 (a) and 2 (b), components common to those in FIGS.

As shown in these figures, the foundation pile 10
The distance in the longitudinal direction is L1 (for example, 50 m), and a pair of conductive wires is provided inside the foundation pile 10 from the pile head 10a to the pile tip 10b shown in FIG. 12 and 13 are buried. These conductive wires 12 and 13 are arranged in parallel at a predetermined interval. The outer peripheral surfaces of the conductive wires 12 and 13 are covered with an insulating material (not shown) (for example, plastics). The conductor 4 is formed in a band shape such that the extending direction of the foundation pile 10 is the longitudinal direction, and the material is made of a carbon fiber bundle. Further, as shown in FIG.
2 and 13 are arranged along the surface of the conductor 4. Further, here, an oscilloscope 15 is provided instead of the oscilloscope 3 shown in FIG. The oscilloscope 15 is of a so-called two-phenomenon type that simultaneously displays two waveforms, and has an input terminal 15a for inputting a signal of a first phenomenon and an input terminal 15b for inputting a signal of a second phenomenon. Each has. The oscilloscope 15 has a built-in CPU (not shown), which performs various operations in the same manner as the CPU built in the oscilloscope 3 shown in FIG.

One end 12a of the conductive wire 12 is connected to the signal generator 1 and the oscilloscope 15 via a probe.
The conductive wire 13 has one end 13 a connected to the oscilloscope 15.
Is connected to the input terminal 15b.

[0064] Operation of the health monitoring sensors M ₁ of the structural member is as follows. Now, in the conductive wire 12 shown in FIG. 3B, one end 12a (pile head 10a)
Obstacle point 1 separated by a distance L2 (for example, 35 m) further downward
It is assumed that damage has occurred in 2b. Here, as for the damage at the failure point 12b, as a result of a tensile load or the like being applied to the foundation pile 10, damage H such as a crack, a crack or breakage occurs in the foundation pile 10 near the failure point 12b. It has occurred with it.

In this state, when a pulse signal Si (see FIG. 4B) is output from the pulse signal generator 1 shown in FIG. 3B to one end 12a of the conductive wire 12 via a probe, The pulse signal Si propagates through the conductive wire 12 toward the other end 12c. And the pulse signal S
Part of i is reflected by the fault point 12b shown in FIG. 4A, and propagates toward the one end 12a as a reflected signal Sri1 (see FIG. 2B). On the other hand, the rest of the pulse signal Si is reflected by the other end 12c, and the reflected signal Sri2
The light propagates toward one end 12a (see FIG. 2B).

Thus, one end 12a of the conductive wire 12
Outputs a reflection signal Sri3 (see FIG. 4C) in which the reflection signal Sri1 and the reflection signal Sri2 are superimposed. In FIG. 4C, a portion corresponding to the reflection signal Sri2 is not shown. Then, the reflection signal Sri3 is input to the oscilloscope 15 from the input terminal 15a. As a result, the oscilloscope 15 displays the waveform of the reflected signal Sri3 shown in FIG. In this figure, a portion E is a portion corresponding to the reflection signal Sri1 shown in FIG.

Next, the CPU (not shown) built in the oscilloscope 15 sends the pulse signal S shown in FIG.
A propagation delay time td between i and the part E is obtained. Here, the distance L2 from the one end 12a to the fault point 12b shown in FIG.
Assuming that the propagation speed of the reflected signal Sri1 at 2 is vp (≒ speed of light c), it is expressed by the following equation (1). L2 = td.vp / 2 (1)

Next, the CPU calculates the propagation delay time td previously obtained from the above equation (1) and the propagation velocity vp which has already been determined.
Are respectively substituted to obtain the distance L2. As a result, FIG.
The position of the failure point 12b in the conductive wire 12 shown in (a) is specified, and the crack, crack, breakage, etc. occurring in the foundation pile 10 is specified.

Further, the pulse signal generator 1 shown in FIG. 3 (a) applies a step-like pulse signal Ss (see FIG. 4 (d)) to one end 12a of the conductive wire 12 shown in FIG. 4 (a). , A part of the pulse signal Ss is reflected by the fault point 2b and propagates toward the one end 2a as a reflected signal Srs1. On the other hand, the pulse signal Ss
Are reflected by the other end 2c and the reflected signal Srs2
The light propagates toward one end 2a (see FIG. 2B).

Thus, one end 12a of the conductive wire 12
From the above, the reflection signal Srs1 and the reflection signal Srs2 described above
Is reflected and the reflected signal Srs3 shown in FIG. 4E is output. In FIG. 4E, the reflection signal S
Illustration of a portion corresponding to rs2 is omitted.

The reflected signal Srs3 is input to the oscilloscope 15 from the input terminal 15a. As a result, the oscilloscope 15 displays the waveform of the reflected signal Srs3 shown in FIG. In this figure, the portion F corresponds to the rising portion of the pulse signal Ss shown in FIG. 4D, and the portion G corresponds to the reflection signal Srs1.

Next, the CPU calculates the propagation delay time td from the rise of the portion F to the rise of the portion G shown in FIG. 4E, and then calculates the propagation delay time td, And the existing propagation velocity vp, respectively,
The distance L2 (see FIG. 4A) is obtained.

Next, the CPU determines the state of the fault point 12b based on the voltages Er and Ei obtained from the waveform of the reflected signal Srs3 shown in FIG. That is, here, the reflection coefficient ρ at the fault point 12b is
The voltage of the pulse signal Ss (incident wave) is Ei (see FIG. 4E), and the voltage of the reflected signal Srs1 (reflected wave) is Er (FIG. 4).
(E)), the impedance of the conductive wire 12 viewed from the fault point 12b toward the other end 12c is Z1, and the impedance of the conductive wire 2 viewed from the one end 2a to the other end 2c when no fault point 12b is present is Z0. Then, it is expressed by the following equation (2). ρ = Er / Ei = (Z1−Z0) / (Z1 + Z0) (2)

First, the CPU obtains the rising voltage Ei of the portion F and the rising voltage Er of the portion G in the reflection signal Srs3 shown in FIG. Next, the CPU substitutes the voltage Ei and the voltage Er into the equation (2) to obtain a reflection coefficient ρ. Here, the voltage Ei =
Assuming that there is a relationship of voltage Er, the reflection coefficient ρ is
It is one. Therefore, in the equation (2), (Z1-Z
Since the relationship of (0) / (Z1 + Z0) = 1 holds, the CPU determines that the impedance Z1 is infinite, that is, the fault point 12b shown in FIG. 3B is completely disconnected.

On the other hand, when the fault point 12b is short-circuited with another conductor or grounded, the voltage Er shown in FIG. 4E has a minus sign and the same level as the voltage Ei. Become. Therefore, in such a case, the reflection coefficient ρ shown in the equation (2) is set to −1, and the CPU
Is determined to be completely short-circuited.

Further, cracks, cracks, etc. occur in the portion near the fault point 12b of the foundation pile 10 shown in FIG.
Immediately after a disconnection occurs at the failure point 12b,
The reflection coefficient ρ takes 1 as described above. That is, it is estimated that the fault point 12b exists in the air.

When the groundwater penetrates into the cracks and cracks of the foundation pile 10 and the fault point 12b is filled with the groundwater, the reflection coefficient ρ changes from 1 to −1 with a change in the impedance of the fault point 2b. And gradually change. Based on the change in the reflection coefficient ρ, the CPU determines whether the fault point 12b is in the air or underground water. In other words, by monitoring the change in the reflection coefficient ρ after the construction of the foundation pile 10, it is possible to know the state of the cracked part and the cracked part of the foundation pile 10.

When the state of the damaged portion of the foundation pile 10 is determined based on the change of the reflection coefficient ρ, the relationship between the change of the reflection coefficient ρ and the state of the damaged portion of the foundation pile 10 is shown by an experiment or the like. The data may be stored in a memory (not shown). In this case, the CPU determines the state of the damaged portion of the foundation pile 10 by applying the actually obtained reflection coefficient ρ to the data stored in the memory.

Further, in the structural member health monitoring sensor M ₁ , it can be determined whether or not the conductive wire 12 and the conductive wire 13 are short-circuited due to the fault H. Here, the short-circuit means not only physical contact but also impedance mismatch. Therefore, even when the conductive wire 12 and the conductive wire 13 are not in physical contact with each other, when the impedance mismatch occurs, the conductive wire 12 and the conductive wire 13 are electrically coupled. Hereinafter, the definition of a short circuit is the same.

Now, in the conductive wire 12, a failure point 12b
And the conductive wires 12 and 13
Is not short-circuited. In this state, the signal generator 1 outputs the pulse signal Si or the pulse signal Ss
Is output to the input terminal 15a of the oscilloscope 15 in the same manner as the operation described above.
3 or the reflection signal Srs3 is input. At this time, no signal is input to the input terminal 15b of the oscilloscope 15.

Thus, the CPU of the oscilloscope 15
Determines the position of the failure point 12b, determines the reflection coefficient ρ using the equation (2), and determines the state of the failure point 12b, that is, the damage state of the foundation pile 10 in the same manner as the above-described operation. I do.

On the other hand, the damage caused to the foundation pile 10 is enormous, and the conductive wire 1 at the failure point H shown in FIG.
2 and the conductive wire 13 are short-circuited. In this state, when the pulse signal Si is output from the signal generator 1, the pulse signal Si is output from one end 1 of the conductive wire 12.
It propagates from 2a to the other end 12c. Then, a part of the pulse signal Si is reflected by the fault point H and propagates toward the one end 12a as the reflected signal Sri1 (see FIG. 2B) and also propagates toward the one end 13a of the conductive wire 13. I do.

Thus, one end 12a of the conductive wire 12
, The reflected signal Sri3 is output to the input terminal 15a of the oscilloscope 15, and from one end 13a of the conductive wire 13, the reflected signal Sri3 'is output to the input terminal 15b of the oscilloscope 15.

As a result, the oscilloscope 15 displays the waveforms of the reflected signal Sri3 and the reflected signal Sri3 '. In addition, the CPU of the oscilloscope 15 specifies the position of the fault point H in the same manner as the above-described operation, and since the reflection signal Sri3 ′ is input, a short circuit (impedance mismatch) occurs at the fault point H. It is determined that it has occurred.

The pulse signal generator 1 generates a step-like pulse signal Ss (see FIG. 4D) from the conductive wire 1.
When the pulse signal Ss is output to one end 12a of the second through the probe, a part of the pulse signal Ss is reflected by the fault point H. As a result, the reflected signal Srs3 and the reflected signal Srs3 'are input to the input terminals 15a and 15b, respectively, and the oscilloscope 15 displays the respective waveforms of the reflected signal Srs3 and the reflected signal Srs3'.

Next, the CPU obtains the reflection coefficient ρ by the above-described procedure based on the voltage Ei and the voltage Er (see FIG. 4E) obtained from the reflection signal Srs3 and the equation (2), and obtains the fault point H Identify the location of Here, in this case, since a short circuit (impedance mismatch) occurs at the fault point H, the sign of the voltage Er is negative. Therefore, the reflection coefficient ρ is −1.

Further, as described above, when specifying the position of the fault point 12b using the pulse signals Si and Ss or grasping the state of cracks at the fault point 12b, the conductor 4 is connected to the conductive wires 12 and 13. By acting to amplify the change in impedance, for example, even if the conductive wires 12, 13 are not directly damaged,
If cracks or the like are generated in the vicinity of the conductive wires 12 and 13, these will be observed as impedance mismatches in the conductive wires 12 and 13, thereby increasing the observation range of the cracks and the like. Become.
In addition, even if minute cracks or the like occur, impedance mismatch between the conductive wires 12 and 13 can be easily observed, so that monitoring accuracy can be improved.

Further, by arranging the conductor 4 along the conductive wires 12 and 13, the effect of concrete on the impedance between the conductive wires 12 and 13 is relatively reduced as compared with the case where the conductor 4 is not arranged. Can be done. Therefore, the influence of the impedance measured between the conductive wires 12 and 13 due to the difference in the amount of water in the concrete constituting the foundation pile 10 can be reduced. In addition, the conductor 4 can relatively reduce the influence of the impedance between the conductive wires 12 and 13 from the reinforcing bars and the like arranged in the foundation pile 10, thereby enabling more accurate monitoring.

Further, in addition to specifying the position of the fault point 12b by the pulse signals Si and Ss or grasping the state of the crack at the fault point 12b, the tester 7
With reference to the change in the resistance value of the conductor 4 observed at
Measurement accuracy can be improved. That is, the conductor 4
A change in resistance value when a compressive load or a tensile load is applied to the tester 7 is checked in advance, and when a change in the resistance value of the conductor 4 is actually Alternatively, it is possible to determine whether any of the compressive loads is acting, and thereby it is also possible to determine, for example, whether the failure point 12b in the conductive wire 12 is caused by tension or compression. .

With reference to the drawings, a structural member soundness monitoring sensor M according to the first embodiment of the present invention will be described.
_{Although the first} embodiment has been described in detail, the present invention is not limited to this embodiment, and a part of a design or the like may be configured to adopt another configuration without departing from the gist of the present invention. Is also good.

[0091] For example, in the health monitoring sensors M ₁ of the above-mentioned structural members, the shape of the conductive wires 12 and 13 are arranged with a predetermined gap in parallel to each other as shown in FIG. 5 (a) Although the configuration has been described, it is also possible to use a twisted line as shown in FIG. Further, in the above-described soundness monitoring sensor M ₁ of the structural member, as shown in FIG. 6A, the conductive wires 12 and 13 are arranged along the surface of the conductor 4. Instead, for example, the conductive wires 12 and 13 are arranged in a coaxial cable shape. Further, as shown in FIG.
By forming the conductors 2 and 13 and the conductor 4 in a coaxial cable shape, the conductive wires 12 and 13 may be arranged inside the conductor 4. Conversely, as shown in FIG. 6C, the conductive wires 12 and 13 may be wound around the outside of the conductor 4. Further, when the conductive wires 12 and 13 are one set and the cross section of the conductor 4 is relatively large, a plurality of sets of the conductive wires 12 and 13 may be arranged.

Further, as the conductive wires 12 and 13, the following ones may be used. (A) A single wire having an aggregate of stranded or extra fine wires as a central conductor, and covered with plastics (dielectric material) having high insulating properties. For example, a conductive metal such as insulated copper in which the outer peripheral edge of a stranded wire is insulated.

(B) a single wire having a diameter of 0.2 mm or less covered with plastics (dielectric material) having high insulation properties;
For example, a thin copper metal wire having a diameter of about 0.05 to 0.1 mm and coated with polyethylene, urethane, or the like.

(C) A narrow (long band) foil material elongated in the longitudinal direction and covered with plastics (dielectric material) having high insulating properties. For example, conductive metal foil such as insulated copper.

The following can be used as the conductor 4. (D) A bundle of carbon long fibers (carbon fiber bundle). In addition, a carbon fiber bundle is used as a central conductor covered with plastics (dielectric material) having high insulation properties. (E) Reinforced plastics (RP) composed of a carbon fiber (CF) reinforcing material and an epoxy resin, and processed into a rod shape by a drawing method (CFRP). (F) A molded body (CFGFRP) of reinforced plastics (RP) composed of a fiber bundle reinforcing material in which carbon fibers (CF) and glass fibers (GF) are bundled, respectively, and a resin such as epoxy or vinyl ester. . (G) A formed body of highly conductive plastics obtained by dispersing and curing a conductive powder. Here, as the conductive powder, for example, carbon (carbon black or graphite) powder or ceramic powder such as titanium carbide or titanium nitride is used. (H) A highly conductive mortar formed by dispersing and curing a conductive powder. Here, the conductive powder is the same as (g).

Further, in the above embodiment, whether or not a short circuit has occurred between one of the conductive wires 12 and 13 and the conductor 4 may be measured. Thereby, the accuracy of monitoring can be further improved.

[Second Embodiment] The one shown in FIG.
Is a diagram showing an overview of health monitoring sensors M ₂ of the structural member of the second embodiment of the present invention. In addition,
In this figure, the same components as those shown in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, a conductive wire 18 is provided instead of the conductive wires 12 and 13 in FIG. As shown in the figure, the conductive wire 18
The central portion is formed in a bent substantially U-shape, one end 18a and the other end 18b are arranged on the pile head 10a side of the foundation pile 10, and the central portion is the pile tip 1
0b. The conductor 4 is formed in a band shape and provided along the conductive wire 18.
In addition, from the pile head 10a of the foundation pile 10 to the pile tip 10b
It is arranged to reach. In addition, conductive wire 1
8 is a signal generator 1 whose one end 18a is connected via a probe.
The other end 18b is connected to the input terminal 15b of the oscilloscope 15.

In the above configuration, it is assumed that the foundation pile 10 (conductive wire 18) is not damaged or the like. In this state, when the pulse signal Si or the pulse signal Ss is output from the signal generator 1, the pulse signal Si or the pulse signal Ss propagates through the conductive wire 18,
The signal is input to the input terminal 15b of the oscilloscope 15. On the other hand, the pulse signal Si or the pulse signal Ss is also input to the input terminal 15a.

As a result, the pulse signal Si or the pulse signal Ss having the same waveform is displayed on the oscilloscope 15 for two phenomena. As a result, since the same waveform is displayed on the oscilloscope 15 with a slight time delay, the CPU determines that the foundation pile 10 (conductive wire 18) is not damaged or the like.

On the other hand, it is assumed that a fault 18c is present in the conductive wire 18 due to damage to the foundation pile 10. In this state, when the pulse signal Si or the pulse signal Ss is output from the signal generator 1, the pulse signal Si or the pulse signal Ss propagates from one end 18a of the conductive wire 18 to the other end 18b. Then, part of the pulse signal Si or the pulse signal Ss
By c, the signal is input to the input terminal 15a of the oscilloscope 15 as the reflection signal Sri1 or the reflection signal Srs1.

On the other hand, the pulse signal Si or the pulse signal S
The remainder of s passes through the fault point 18c of the conductive wire 18 and becomes a transmission signal Sti1 or a transmission signal Sts1.
The input terminal 15 of the oscilloscope 15 via the other end 18b
b.

As a result, the oscilloscope 15 displays the respective waveforms of the reflection signal Sri1 or the reflection signal Srs1, and the transmission signal Sti1 or the transmission signal Sts1. Accordingly, the CPU determines the state of the fault point 18c (the foundation pile 10) from the level ratio between the reflection signal Sri1 (or the reflection signal Srs1) and the transmission signal Sti1 (or the transmission signal Sts1).

That is, the CPU sets the transmission signal Sti1
If (the transmission signal Sts1) is zero, it is determined that the fault point 18c is completely disconnected. On the other hand, C
PU is the reflection signal Sri1 (or the reflection signal Srs1)
Is the transmission signal Sti1 (or the transmission signal Sts).
If the level is larger than the level of 1), it is determined that the damage of the fault point 18c is large, and if the opposite is true, the fault point 18c is determined.
It is determined that the damage of c is small.

At this time, since the conductor 4 is arranged along the conductive wire 18, the pulse signals Si and Ss
The position of the failure point 18c by using
When grasping the state of cracks in c, the conductor 4
As a result, the same operation and effect as those of the first embodiment can be obtained, thereby enabling highly accurate monitoring.

In addition to this, if it is determined whether a tensile load or a compressive load is acting on the conductor 4 based on a change in the resistance value of the conductor 4 observed in the tester 7, more accurate accuracy can be obtained. High measurement is possible.

The conductive wires 18 and the conductors 4 in the second embodiment are shown in (a) to (c) and (d) to (h) in the first embodiment. Can be used. In the second embodiment, the conductive wire 18 has a shape as shown in FIG. 5C, but instead has a shape as shown in FIG. 5D. A linear shape may be used. Further, in the second embodiment, as shown in FIG. 6A, the conductive wire 18 is arranged along the surface of the conductor 4, but instead, for example, FIG.
As shown in (b), by forming the conductive wire 18 and the conductor 4 into a coaxial cable shape, the conductive wire 18 may be arranged inside the conductor 4. Conversely, as shown in FIG. 6C, the conductive wire 18 may be wound around the conductor 4. Further, when the cross section of the conductor 4 is larger than that of the conductive wire 18, a plurality of the conductive wires 18 may be arranged.

In the second embodiment, the measurement as to whether or not a short circuit has occurred between the conductive wire 18 and the conductor 4 is performed in the same manner as in the method described in the first embodiment. May be performed. Thereby, the accuracy of monitoring can be further improved.

As described above, in the structural member soundness monitoring sensors M ₁ and M ₂ according to the first and second embodiments described above, the foundation pile 10 is pulled within a range slightly exceeding the elastic strain. Even after returning to the original state after receiving a load or the like, a part of the carbon fiber bundle of the conductive wire 12, 13, or 18 is broken at the time of receiving the above strain. Therefore, according to the structural member health monitoring sensors M ₁ and M ₂ according to the first and second embodiments, even in the case described above, a tensile load or the like is applied to the past foundation pile. Can be determined. In other words, according to the structural member soundness monitoring sensors M ₁ and M ₂ according to the first and second embodiments, it is possible to obtain an effect that the damage state of the foundation pile 10 can be continuously monitored. it can. Also,
According to the structural member health monitoring sensors M ₁ and M ₂ according to the first and second embodiments, since the conductive wire 12, 13 or 18 is used instead of the conventional optical fiber, Even when the pile 10 is made of concrete, the pile 10 has durability. Further, according to the structural member soundness monitoring sensors M ₁ and M ₂ according to the first and second embodiments, unlike the conventional one, a plurality of terminals are not provided at an intermediate point of the conductive wire rod. The damaged portion of the foundation pile 10 can be specified by a low-cost and simple configuration.

The above is the outline of the structural member soundness monitoring sensor when the TDR measuring method is applied. Next, the soundness of the structural member is applied by applying the principle of the VNA (Vector Network Analyzer) measuring method. An example in which monitoring is performed will be described as third to fifth embodiments.

[0111] [Third Embodiment] Next, a description is given of a third overview of the health monitoring sensors M ₃ of the structural member according to an embodiment of the present invention with reference to FIG. In this figure, the same components as those in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted.
In health monitoring sensor M ₃ of the structural member shown in FIG. 8, instead of the signal generator 1 and the oscilloscope 15 shown in FIG. 3 (a), the network analyzer 30, the power splitter 31 is provided.

In FIG. 8, the network analyzer 3
Reference numeral 0 denotes a measuring device capable of analyzing a signal of 5 Hz to several tens of GHz, and outputs a high-frequency signal Sh to be described later.
High frequency signal Sh1 and reflected signals Sr, S input
It has a function to determine the state of the conductive wires 12, 13 (foundation pile 4) based on r '. Specifically, the network analyzer 30 obtains the phase characteristics and the amplitude characteristics in the frequency domain of the high-frequency signal Sh1 and the reflected signals Sr and Sr ', and obtains the transmission line loss and the signal propagation delay time based on these. And so on.

This network analyzer 30 has one output terminal 30a and three input terminals 30b, 30c and 30d. A high frequency signal Sh is output from the output terminal 30a. Further, the high frequency signal Sh1 and the reflection signal Sr are input to the input terminal 30b. Further, the input terminal 30 c is connected to one end 13 a of the conductive wire 13, and the reflected wave S
r 'is input. In this embodiment, no signal is input to the input terminal 30d of the network analyzer 30. The details of the operation of the network analyzer 30 will be described later.

The power splitter 31 divides the input high-frequency signal Sh into a high-frequency signal Sh1 and a high-frequency signal Sh2, and is composed of shunt resistors R1 and R2. That is, one end of each of the shunt resistors R1 and R2 is connected to the output terminal 30a of the network analyzer 30, and the other end of the shunt resistor R1 is connected to the input terminal 30b of the network analyzer 30. The other end of the shunt resistor R2 is connected to the conductive wire 12.

[0115] Next, the operation of the health monitoring sensors M ₃ of the structural member in the present embodiment. In FIG. 8, it is assumed that a fault point 12 b is present in the middle of the conductive wire 12. In this state,
When the high-frequency signal Sh is output from the output terminal 30a of the network analyzer 30, the high-frequency signal Sh is split into a high-frequency signal Sh1 and a high-frequency signal Sh2 by the power splitter 31, and the high-frequency signal Sh1 is The signal is input to the input terminal 30b. Here, the high frequency signal Sh2 has a sine wave shape.

On the other hand, the high frequency signal Sh2 is input to one end 12a of the conductive wire 12 via the shunt resistance R2 of the power splitter 31. Further, the high frequency signal Sh2 is
Reflected by the fault point 12b, the reflected signal Sr
The light propagates in the direction of one end 12a. Then, the reflected signal Sr
Is input to the input terminal 30b of the network analyzer 30 via the power splitter 31.

Thus, the network analyzer 30
Calculates the phase characteristic and the amplitude characteristic in the frequency domain of the input high-frequency signal Sh1 and the reflected signal Sr by changing the frequency of the high-frequency signal Sh2 one after another. Next, the network analyzer 30 performs an inverse Fourier transform on each of the information of the phase characteristic and the amplitude characteristic, and
A waveform on the time axis similar to the reflected signal Sri3 or the reflected signal Srs3 shown in FIG. 4C or FIG. 4E is obtained.

That is, the network analyzer 30
Calculates the phase and amplitude characteristics of a transmission path using a high-frequency signal Sh2 in a predetermined frequency domain instead of inputting a pulse-shaped signal, and converts the information in the frequency domain into the information in the time domain to produce a pulse-shaped signal. (The pulse-like signal input can theoretically be obtained from the phase and amplitude characteristics of the entire frequency domain. Here, such a troublesome method is used. This is because there is an advantage that the state of the transmission path can be examined in more detail.) Now, by these procedures, FIG.
After obtaining a waveform similar to that shown in (c), a propagation delay time td is obtained from the waveform. Then, the network analyzer 30, and a previously described with the propagation delay time td (1) equation by determining the distance L ₂ from one end 12a of the conductive wire 12 shown in FIG. 8 to the point of failure 12b, fault point 12b Identify the location of

When performing the above-described inverse Fourier transform, the network analyzer 30 performs the inverse Fourier transform on the noise component cut. This allows
The result of the inverse Fourier transform is not affected by noise.

The resolution of the network analyzer 30 increases in proportion to the frequency of the high frequency signal Sh. For example, when the frequency of the high-frequency signal Sh is set to 110 GHz, under the influence of the covering material that covers the conductive wire 12,
The resolution is 60% to 90% of 2.7 mm (one wavelength).

According to the structural member health monitoring sensor M ₃ , it is possible to determine whether or not a short circuit (impedance mismatch) has occurred between the conductive wires 12 and 13. Now, the conductive wires 12 and 1
No short-circuit (impedance mismatch) has occurred between the conductive wire 3 and the conductive wire 12 and a failure point 12b due to damage to the foundation pile 10 or the like exists. In this state, the output terminal 3 of the network analyzer 30
0a, the high frequency signal Sh is output from the input terminal 30b of the network analyzer 30.
1 and the reflection signal Sr from the conductive wire 12 are input, and no signal is input to the input terminal 30c. Therefore, the network analyzer 30 generates a short circuit between the conductive wires 12 and 13 based on the signal. In addition to determining that there is no signal, the distance to the fault point 12b is determined from the phase characteristics and amplitude characteristics of the high-frequency signal Sh1 and the reflected signal Sr.

On the other hand, if the foundation pile 10 has been seriously damaged or the foundation pile 10 has cracks or the like, a short circuit has occurred between the conductive piles 12 and 13 at the failure point H shown in FIG. (Impedance mismatch). In this state, the network analyzer 30
When the high frequency signal Sh is output from the output terminal 30a of
Through the above-described operation, a part of the high-frequency signal Sh2 is reflected by the fault point H and propagates as the reflected signal Sr toward the one end 2a. At the same time, the remainder of the high-frequency signal Sh2 is used as the reflected signal Sr ′ as one end 13a of the conductive wire 13.
Propagate to

As a result, one end 12a of the conductive wire 12
, The reflected signal Sr is output to the input terminal 30 b of the network analyzer 30 via the power splitter 31, and the reflected signal Sr ′ is output from the one end 13 a of the conductive wire 13 to the input terminal 30 c of the network analyzer 30. Is done.

At this time, the network analyzer 30
After obtaining the waveforms of the reflection signal Sr and the reflection signal Sr ′ in the same manner as in the above-described operation, the position of the fault point H is specified based on the waveforms, and the reflection signal Sr ′ is input. Therefore, it is determined that a short circuit (impedance mismatch) has occurred at the fault point H. The procedure for identifying the fault point H is the same as the procedure in the monitoring sensors M ₁ of the structural member according to the first embodiment described above.

Further, at this time, the conductive wires 12, 13
The conductor 4 arranged along the line functions as having the same operation and effect as the conductor 4 in the above-described first embodiment, and as a result, compared to the case where the conductor 4 is not arranged, Accuracy will be improved.

In the structural member soundness monitoring sensor M ₃ according to this embodiment, the conductive wires 12 and 13 shown in the items (a) to (c) in the first embodiment are used as the conductive wires 12 and 13. May be used. Further, as the conductor 4, the conductors shown in the items (d) to (h) in the above-described first embodiment may be used. Further, the shape of the conductive wires 12, 13 may be any of the shapes shown in FIG. 5 (a) or (b). The arrangement of the conductive wires 12, 13 and the conductor 4 may be any of those shown in FIGS. 6 (a) to 6 (c).

Further, in addition to the above-described method for determining the soundness of the foundation pile 10, a change in the resistance value of the conductor 4 observed in the tester 7 causes either a tensile load or a compressive load to act on the conductor 4. May be determined, and in this case, more accurate measurement can be performed. In the third embodiment, the measurement as to whether or not a short circuit has occurred between one of the conductive wires 12 and 13 and the conductor 4 is performed.
13 may be performed in the same procedure as when determining whether a short circuit has occurred. Thereby, the accuracy of monitoring can be further improved.

[0128] [Fourth Embodiment] FIG 9 is a diagram showing a schematic configuration of a health monitoring sensor M ₄ of the structural member according to the fourth embodiment of the present invention. In this figure, parts corresponding to the respective parts in FIG.
The description is omitted. 9, a directional coupler 32 is provided instead of the power splitter 31 shown in FIG.

The directional coupler 32 has terminals 32a, 32b
And the high frequency signal Sh1 and the high frequency signal Sh2 input to the terminal 32a.
It has a function of branching to. That is, the directional coupler 32 outputs the high-frequency signal Sh1 from the terminal 32c and outputs the high-frequency signal Sh2 from the terminal 32b. The terminal 32 a of the directional coupler 32 is connected to the output terminal 30 a of the network analyzer 30. Further, the terminal 32 b is connected to one end 1 of the conductive wire 12.
2a, and the terminal 32c is connected to the input terminal 30b of the network analyzer 30.

[0130] Next, the operation of the health monitoring sensors M ₄ of the structural member. In FIG.
Now, a great deal of damage has occurred in the foundation pile 10 or a crack or the like has occurred in the foundation pile 10, and a failure point H shown in FIG.
It is assumed that a short circuit (impedance mismatch) has occurred between the conductive wire 12 and the conductive wire 13 in FIG.

In this state, when the high frequency signal Sh is output from the output terminal 30a of the network analyzer 30, the high frequency signal Sh is branched by the directional coupler 32 into a high frequency signal Sh1 and a high frequency signal Sh2. Then, the high frequency signal Sh1 is transmitted to the network analyzer 30.
Of the high-frequency signal S
After h2 is input to one end 12a of the conductive wire 12,
It propagates through the conductive wire 12.

The high-frequency signal Sh2 is reflected at the fault point H and propagates through the conductive wire 13 as a reflected signal Sr.
0c is input. Thereby, the network analyzer 30 performs the high-frequency signal Sh in the same manner as the above-described operation.
1 and the waveform of the reflection signal Sr, the position of the fault point H is specified based on the waveform, and the reflection signal Sr is determined.
Is input, it is determined that a short circuit (impedance mismatch) has occurred at the fault point H. Here, the procedure for identifying the fault point H is the same as the procedure in the health monitoring sensors M ₃ of the structural member according to the third embodiment.

In the structural member soundness monitoring sensor M ₄ according to this embodiment, the conductive wires 12 and 13 are the same as those shown in the above-mentioned first embodiment (a) to (c). May be used. Further, as the conductor 4, the conductors shown in (d) to (h) in the first embodiment may be used. Further, the shapes of the conductive wires 12 and 13 are as follows:
Any of the shapes shown in FIGS. 5A and 5B may be used. The arrangement of the conductive wires 12, 13 and the conductor 4 may be any of those shown in FIGS. 6 (a) to 6 (c).

Further, in addition to the above-described method of determining the soundness of the foundation pile 10, a change in the resistance value of the conductor 4 observed in the tester 7 causes either a tensile load or a compressive load to act on the conductor 4. May be determined, and in this case, more accurate measurement can be performed. Further, in the fourth embodiment, the measurement as to whether or not a short circuit has occurred between one of the conductive wires 12 and 13 and the conductor 4 is performed by the above-described conductive wires 12 and 13.
13 may be performed in the same procedure as when determining whether a short circuit has occurred. Thereby, the accuracy of monitoring can be further improved.

[0135] The Fifth Embodiment those shown in FIG. 10 illustrates a health monitoring sensor M ₅ of the structural member of the fifth embodiment of the present invention. In health monitoring sensors M ₅ of the structural member,
In the structural member health monitoring sensor M3 of the _third embodiment described above, the switch 33, the directional coupler 34, the directional coupler 35, and the conductive wire are used instead of the conductive wires 12 and 13. 18 is provided.

The switch 33 is a switch for outputting the high-frequency signal Sh2 to either the directional coupler 34 or the directional coupler 35. This switch 33
The movable piece 33e and the movable piece 33f are connected to the terminal 33b and the terminal 33d by a controller (not shown) or manually.
Side, or one of the terminals 33a and 33c. Also, the terminal 33b and the terminal 33c
Is connected to the other end of the shunt resistor R2 of the power splitter 31.

The directional coupler 34 has the same configuration as the directional coupler 32 shown in FIG. 9, and its terminal 34a is connected to the movable piece 33e, its terminal 34b is connected to one end 18a of the conductive wire 18, and Terminal 34c is network analyzer 3
0 input terminals 30c. The directional coupler 34 receives the high-frequency signal Sh input to the terminal 34a.
2 to the terminal 34b, and the reflected signal Sr (or the transmitted signal St) input to the terminal 34b to the terminal 34b.
c).

As shown in the figure, the conductive wire 18 is formed in a substantially U-shape with its central portion bent.
One end 18a and the other end 18b are the pile head 1 of the foundation pile 10.
0a side, and the central part is the pile tip 10b.
Is arranged to reach. The conductor 4 is formed in a strip shape and provided along the conductive wire 18, and is disposed so as to extend from the pile head 10 a of the foundation pile 10 to the pile tip 10 b.

The directional coupler 35 has the same configuration as the directional coupler 34. The terminal 35a is connected to the movable piece 33f, and the terminal 35b is connected to the other end 18 of the conductive wire 18.
b, the terminal 35c is connected to the input terminal 30d of the network analyzer 30, respectively.

The directional coupler 35 outputs the high-frequency signal Sh2 input to the terminal 35a to the terminal 35b, and outputs the transmission signal St (or reflection signal Sr) input to the terminal 35b to the terminal 35c. Has a function.

[0141] Next, the operation of the health monitoring sensors M ₅ of the structural member. In FIG. 10, a fault 18 c is present in the conductive wire 18 and the movable piece 33 e and the movable piece 33
f is switched to the terminal 33b side and the terminal 33d side, respectively.

In this state, when the high-frequency signal Sh is output from the output terminal 30a of the network analyzer 30, the high-frequency signal Sh is divided into the high-frequency signal Sh1 and the high-frequency signal Sh2 by the power splitter 31. Then, while the high-frequency signal Sh1 is input to the input terminal 30b of the network analyzer 30, the high-frequency signal Sh2 is input to one end 18a of the conductive wire 18 via the shunt resistor R2, the switch 33, and the directional coupler. After that, it propagates through the conductive wire 18.

Then, a part of the high-frequency signal Sh2 is reflected by the fault point 18c, and is input to the input terminal 30c of the network analyzer 30 via the directional coupler 34 as a reflected signal Sr. On the other hand, the remainder of the high-frequency signal Sh2 passes through the fault point 18c and is input to the input terminal 30d of the network analyzer 30 via the directional coupler 35 as the transmission signal St.

As a result, the network analyzer 30
, As in the operation of the fourth embodiment of the structural health monitoring sensors M ₄ of the members, the high-frequency signal Sh1,
The phase characteristics and the amplitude characteristics of the reflection signal Sr and the transmission signal St are obtained. Next, the network analyzer 30
The inverse Fourier transform is performed on the phase characteristics and the amplitude characteristics of the high-frequency signal Sh1 and the reflection signal Sr, and the waveforms similar to those shown in FIG. 4C or FIG. The propagation delay time td is obtained, and based on this, the distance from one end 18a of the conductive wire 18 shown in FIG. 9 to the fault point 18c is obtained.

The network analyzer 30 determines the point of failure 1 based on the level ratio between the reflected signal Sr and the transmitted signal St.
The state of 8c (foundation pile 10) is determined. That is, CP
If the level of the transmission signal St is zero, U determines that the fault point 18c is completely disconnected. On the other hand, when the level of the reflected signal Sr is larger than the level of the transmitted signal St, the network analyzer 30
It is determined that the damage of the fault point 18c is small in the reverse case.

It is also assumed that the movable piece 33e and the movable piece 33f of the switch 33 have been switched from the state shown in the figure to the terminals 33a and 33c by the control device or manually. In this state, the high frequency signal Sh is output from the output terminal 30a of the network analyzer 30.
Is output, the high-frequency signal Sh is output from the high-frequency signal Sh1 by the power splitter 31 in the same manner as described above.
And the high-frequency signal Sh2. The high-frequency signal Sh2 is supplied to the other end 18b of the conductive wire 18 via the shunt resistor R2, the switch 33, and the directional coupler 35.
, And propagates through the conductive wire 18.

Then, a part of the high-frequency signal Sh2 is reflected by the failure point 18c and is input to the input terminal 30d of the network analyzer 30 via the directional coupler 35 as the reflected signal Sr. On the other hand, the rest of the high-frequency signal Sh2 is transmitted through the fault point 18c and is input to the input terminal 30c of the network analyzer 30 via the directional coupler 34 as a transmitted signal St. Thereby, the network analyzer 30 calculates the distance from the other end 18b to the fault point 18c in the same manner as the above-described operation,
The state of the failure point 18c (the foundation pile 10) is determined.

At this time, since the conductor 4 is arranged along the conductive wire 18, the position of the fault 18c is specified by the pulse signals Si and Ss, or the fault 18c is specified.
When grasping the state of cracks in the above, the same operation and effect as in the first to fourth embodiments are performed by the conductor 4.
As a result, an effect can be obtained, thereby enabling highly accurate monitoring.

In addition to this, if it is determined whether a tensile load or a compressive load is acting on the conductor 4 based on a change in the resistance value of the conductor 4 observed in the tester 7, more accurate accuracy can be obtained. High measurement is possible.

[0150] In the health monitoring sensors M ₅ of the structural member according to this embodiment, as the conductive wire 18, used as shown in (a) through (c) term in the first embodiment described above You may do so. Further, as the conductor 4, the conductors shown in the items (d) to (h) in the above-described first embodiment may be used. Further, the shape of the conductive wire 18 may be any of the shapes shown in FIGS. 5C and 5D. The arrangement of the conductive wire 18 and the conductor 4 may be any of those shown in FIGS.

Further, in addition to the above-described method of determining the soundness of the foundation pile 10, a change in the resistance value of the conductor 4 observed in the tester 7 causes either a tensile load or a compressive load to act on the conductor 4. May be determined, and in this case, more accurate measurement can be performed.

In the fifth embodiment, the measurement as to whether or not a short circuit has occurred between the conductive wire 18 and the conductor 4 is performed in the first or third embodiment. , 13 may be performed in the same procedure as when determining whether a short circuit has occurred. Thereby, the accuracy of monitoring can be further improved.

Although the first to fifth embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to the first to fifth embodiments. ,
Even a design change or the like within a range not departing from the gist of the present invention is included in the present invention.

For example, in the first to fifth embodiments, an example in which monitoring is performed on the foundation pile 10 has been described. However, the present invention is not limited to this. It may be a structural member. Of these, for structures, RC construction, SRC
It can be applied to all concrete structures including structures, etc., and the members can be applied to various members and parts of the structure, such as pillars, beams, walls, plates such as slabs, foundations such as stairs, piles, etc. Applicable to:

The conductors 12, 13, 18 and the conductor 4 are
It is not necessary to be embedded in the structural member, and it may be attached to the surface of the structural member. In this case, if necessary, apply a resin or paint or paste a sheet of plastics, etc.,
Protect the sensor. Such a method of use is very effective as a monitoring method for assuring the performance and confirming the performance, since the seismic reinforcement of existing structures and structural members by the carbon fiber sheet has been widely performed.

[0156]

As described above, according to the present invention,
Even if the structural member returns to its original state after receiving a tensile load or the like within the range of elastic strain, a part of the fiber bundle of the conductive wire breaks at the time of receiving the elastic strain. Therefore,
According to the present invention, in such a case, it is possible to determine that a tensile load or the like has been applied to a past structural member. In other words, according to the present invention, the effect of being able to continuously monitor the damage state of the structural member can be obtained. Also,
According to the present invention, since a conductor is used instead of a conventional optical fiber as a sensor, the durability is high even if the structural member is made of concrete. Further, according to the present invention, a damaged portion of a structural member can be specified by a low-cost and simple configuration without providing a plurality of terminals at an intermediate point of a conductive wire unlike a conventional one. In the present invention, since the conductor is arranged along the conductor, it is easy to grasp the transmission characteristics of the conductor, and it is possible to reduce an external electrical influence on the conductor and the like. High monitoring is possible. Further, according to the fourth to sixth aspects of the present invention, since a high-frequency signal is used, an effect is obtained that the resolution of monitoring can be improved in proportion to the frequency of the high-frequency signal. Further, according to the invention of claim 7, by monitoring the electric resistance of the conductor itself in addition to the measurement using the conductive wire, more accurate monitoring can be realized. Furthermore, according to the invention described in claim 8, when the structural member is damaged and cracks or the like occur, the conductor is damaged before the conductor, and the impedance is changed around the conductor accordingly. It will be. Thus, unlike the case where only the conductor is simply provided in the structural member, minute cracks or the like that do not change the electrical characteristics of the conductor at all can be detected satisfactorily and have high accuracy. Monitoring becomes possible.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a basic configuration of a structural member health monitoring sensor of the present invention.

FIG. 2 is a view for explaining the operation of the structural member health monitoring sensor shown in FIG. 1;

FIG. 3 is a view showing a specific configuration of a structural member health monitoring sensor according to the first embodiment of the present invention.

FIG. 4 is a view for explaining the operation of the structural member health monitoring sensor shown in FIG. 3;

FIG. 5 is a view showing an example of the shape of a conductive wire used in the first to fifth structural member soundness monitoring sensors of the present invention.

FIG. 6 is a diagram showing an example of the arrangement of conductive wires and conductors used in the first to fifth structural member health monitoring sensors of the present invention.

FIG. 7 is a diagram showing a specific configuration of a structural member health monitoring sensor according to a second embodiment of the present invention.

FIG. 8 is a diagram showing a specific configuration of a structural member health monitoring sensor according to a third embodiment of the present invention.

FIG. 9 is a diagram showing a specific configuration of a structural member health monitoring sensor according to a fourth embodiment of the present invention.

FIG. 10 is a diagram showing a specific configuration of a structural member health monitoring sensor according to a fifth embodiment of the present invention.

11A and 11B are diagrams for illustrating means for solving the problem in the present invention, and FIG. 11A is a cross-sectional view illustrating a structural member in which a conductive wire and a conductor disposed along the conductive wire are embedded. (B) is a cross-sectional view showing a structural member in which only a conductive wire is embedded.

FIGS. 12A and 12B are diagrams showing means for solving the problem in the present invention, wherein FIGS. 12A and 12B are diagrams around the conductor shown in FIGS. 11A and 11B, respectively. FIG. 4 is a diagram showing what defines the electrical characteristics in the vicinity of a crack.

[Explanation of symbols]

M, M ₁ , M ₂ , M ₃ , M ₄ , M ₅ Structural member soundness monitoring sensor 1 Pulse signal generator Si, Ss Pulse signal Sri3, Srs3 Sri3 ′, Srs3′Sr, S
r 'reflection signal 2,12,13,18 conductive wire 2a, 12a, 13a, 18a one end 2c, 12c, 13b, 18b other end 12b, 18c fault point 4 conductor 7 tester 3,15 oscilloscope Sti1, Sts1, St transmission Signal 10 Foundation pile (structural member) 30 Network analyzer

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kiyoshi Ishii 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation (72) Inventor Hiroshi Inada 1-2-3 Shibaura, Minato-ku, Tokyo Shimizu Corporation (72) Inventor Minoru Sugita 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation F-term (reference) 2F063 AA01 AA30 BA14 BD07 CA13 DA02 DA05 DD08 FA00 FA14 FA18 FA20 PA01

Claims (8)

[Claims] 1. A conductive wire disposed inside or on a surface of a structural member, a conductive conductor closely disposed along the conductive wire, and a pulse signal supplied to one end of the conductive wire. A pulse signal supply unit that determines a damaged position of the structural member and determines a damaged state of the structural member based on the pulse signal and a reflected signal output from one end of the conductive wire. A health monitoring sensor for a structural member characterized by comprising: 2. The structural member health monitoring sensor according to claim 1, wherein the structural member has at least one pair of the conductive wires extending in the same direction and being close to each other. The pulse signal supply unit is configured to supply the pulse signal from at least one end of the pair of conductors from an end thereof, and the determination unit includes the pulse signal and one end of the conductor. Based on the first reflected signal output from the unit, and the second reflected signal output from the other end of the conductor,
A structural member soundness monitoring sensor, wherein a damaged position of the structural member is specified and a damaged state of the structural member is determined. 3. The health monitoring sensor for a structural member according to claim 1, wherein the determination unit receives the pulse signal, a reflection signal output from one end of the conductor, and the other end of the conductor. A structural member soundness monitoring sensor, wherein a damaged position of the structural member is specified based on the transmitted signal output. 4. A conductive wire disposed inside or on a surface of a structural member, a conductive conductor closely disposed along the conductive wire, and a high frequency inputting a high frequency signal to one end of the conductive wire. A signal supply unit; a high-frequency signal supply unit; and a determination unit configured to specify a damaged position of the structural member based on a reflected signal output from one end of the conductive wire and determine a damaged state of the structural member. A structural member health monitoring sensor, comprising: a sensor; 5. The health monitoring sensor for a structural member according to claim 4, wherein the structural member has at least a pair of the conducting wires extending in the same direction and being close to each other. The high-frequency signal supply unit is configured to supply the high-frequency signal to at least one of the pair of conductors from an end thereof, and the determination unit includes the high-frequency signal and one end of the conductor. Based on the first reflected signal output from the unit, and the second reflected signal output from the other end of the conductor,
A structural member soundness monitoring sensor, wherein a damaged position of the structural member is specified and a damaged state of the structural member is determined. 6. The health monitoring sensor for a structural member according to claim 4, wherein the determination unit receives the high-frequency signal, a reflection signal output from one end of the conductor, and the other end of the conductor. A structural member soundness monitoring sensor, wherein a damaged position of the structural member is specified based on the transmitted signal output. 7. The health monitoring sensor for structural members according to claim 1, wherein at least two or more terminals are connected to the conductor, and the terminal is connected between the terminals. A structural member health monitoring sensor to which a resistance measuring means for measuring a resistance value is connected. 8. The sensor for monitoring the health of a structural member according to claim 1, wherein a breaking extension of the conductor is smaller than a breaking extension of the conductor. Health monitoring sensor for structural members.