Method for monitoring the condition of a resin inspection track and resin inspection track

Abstract

To quantitatively monitor the condition of a resin inspection road using a simple method and means without relying on visual inspection.SOLUTION: Multiple strain gauges 6 are attached as strain measuring means to an underside of a floor material 1 in the longitudinal center of a resin inspection path, lined up in the width direction. A data logger 8 is connected to each strain gauge 6 via wiring 7. The strain values measured by the strain gauges 6 and the deflection data calculated from the strain values are recorded in the data logger 8. The recorded data is compared with a preset soundness judgment standard to judge the soundness of the inspection path. With this configuration, there is no need to visually check the condition of the inspection path, and quantitative condition monitoring can be easily performed.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a method for monitoring the state of a resin inspection path for performing maintenance inspections of bridges and the like, and a resin inspection path that is the object of the state monitoring method.

Background Art

[0002] Steel bridges such as roads and railways generally undergo regular inspection work to visually check for the presence or absence of surface rust and fatigue cracks, and are maintained by repairing them as necessary. In addition, in order to improve the efficiency of bridge maintenance work, a system for continuously monitoring fatigue cracks has also been proposed. For example, in the fatigue crack monitoring system proposed in Patent Document 1, a linear sensor is attached to a location where cracks are likely to occur in a bridge, and when the linear sensor is energized by a data logger connected to both ends of the linear sensor, the resistance value is measured, and the measurement data is transmitted to and displayed on a management center, so that the management center can remotely monitor the state of the bridge, such as the degree of crack progress.

[0003] On the other hand, inspection paths attached to bridges for bridge inspection and repair have conventionally been mostly made of steel, but in recent years, in consideration of weight reduction and corrosion resistance, they are often manufactured from fiber reinforced resin (FRP) (see, for example, Patent Document 2). In the resin inspection path typified by the FRP inspection path, since rust and thinning do not occur on the surface, there is a problem that it is more difficult to judge deterioration by appearance than in the case of steel ones. In addition, a monitoring system for monitoring the state of the resin inspection path is not currently found.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Therefore, the objective of the present invention is to enable quantitative monitoring of the condition of resin inspection paths using simple methods and means, without relying on visual inspection. [Means for solving the problem]

[0006] To solve the above problems, the present invention employs a configuration (Configuration 1) in which a strain measuring means is attached to the resin inspection path, and the soundness of the resin inspection path is determined using a preset soundness determination criterion based on the strain value measured by the strain measuring means or the amount of deflection calculated from the strain value.

[0007] According to the above configuration 1, there is no need to visually check the condition of the resin inspection path, and quantitative condition monitoring can be easily performed based on the strain value at any position of the resin inspection path or the amount of deflection calculated from that strain value.

[0008] In the above configuration 1, if a hollow section is provided in the floor material constituting the resin inspection path, the wiring connected to the strain measuring means can be housed in the hollow section of the floor material (configuration 2), thereby making it less likely for the wiring to be damaged.

[0009] In the above configuration 1 or 2, a strain gauge can be used as the strain measuring means (configuration 3).

[0010] Furthermore, the resin inspection path of the present invention can be configured such that, in accordance with the condition monitoring method of configuration 2 above, a strain measuring means is attached to the resin inspection path in which a hollow section is provided in the floor material, and wiring connected to the strain measuring means is housed in the hollow section of the floor material (configuration 4).

[0011] In the resin inspection path of configuration 4 described above, a data transmission means that transmits data of strain values ​​measured by the strain measuring means to the outside is connected to the wiring, and the data transmission means can be installed in the hollow part of the floor material (configuration 5). In this way, the data transmission means is protected within the hollow part of the floor material, and the strain value data transmitted from the data transmission means is sent to an office such as a management center located away from the inspection path installation site, where the condition of the resin inspection path can be remotely monitored. [Effects of the Invention]

[0012] As described above, the present invention provides a resin inspection path equipped with a strain measuring means, enabling easy and quantitative monitoring of the resin inspection path's condition based on strain values ​​or the amount of deflection calculated from those strain values, without relying on visual inspection. Therefore, it can greatly contribute to the efficient maintenance and management of resin inspection paths. [Brief explanation of the drawing]

[0013] [Figure 1] Side view of the resin inspection passage of the first embodiment [Figure 2] Cross-sectional view along line II-II in Figure 1 (explanatory diagram of the method for monitoring the condition of the resin inspection path) [Figure 3] Perspective view of the area near the cross-section in Figure 2, seen from below. [Figure 4] Diagram illustrating the method for monitoring the condition of a resin inspection path according to the second embodiment. [Figure 5] Perspective view showing a modified strain gauge mounting position. [Modes for carrying out the invention]

[0014] Embodiments of the present invention will be described below with reference to the drawings. Figures 1 to 3 show a resin inspection walkway and a method for monitoring its condition according to the first embodiment. This resin inspection walkway (hereinafter also simply referred to as "inspection walkway") comprises a floor material 1 that is placed and fixed on a support frame (bracket) 10 that extends from a structure such as a bridge (not shown), support columns 2 erected at intervals on both sides of the floor material 1, a plurality of handrails 3 attached to the support columns 2, and toe plates 4 extending along both sides of the floor material 1. The support columns 2 consist of a main body 2a to which the handrails 3 are attached, and a reinforcing part 2b attached to the lower end of the main body 2a. The floor material 1, support columns 2, handrails 3 and toe plates 4 are made of FRP, but the reinforcing part 2b of the support columns 2 may be made of stainless steel or steel plated for rust prevention purposes, with an emphasis on strength and rigidity.

[0015] As shown in Figures 2 and 3, the floor material 1 is a hollow plate-like structure consisting of an upper surface 11, a lower surface 12, and both side surfaces 13, and is a one-piece molded product (integrating the main girder and the floor slab) with multiple ribs 14 extending longitudinally between the upper surface 11 and the lower surface 12 at multiple locations in the width direction. The lower surface 12 of the floor material 1 is provided with circular mounting holes 15 near the fastening points between the side surfaces 13 of the floor material 1 and each support column 2, and these mounting holes 15 can be used to fasten the support columns 2 to the floor material 1.

[0016] Furthermore, as shown in Figures 1 to 3, the support column 2 is an L-shaped member in cross-section, with both its main body 2a and reinforcing portion 2b consisting of two strip-shaped sections. One strip-shaped section of each is fixed to the side surface 13 of the flooring material 1 with a bolt and nut that penetrates outward from the inner surface of the side surface 13, while the other strip-shaped sections are fixed to each other with a bolt and nut that penetrates each other.

[0017] Each handrail 3 is a round pipe-shaped member that penetrates the other strip portion of the multiple support posts 2 arranged in the longitudinal direction of the floor material 1, and is fixed to the support posts 2 at the front and rear of the penetration point with fasteners 5.

[0018] The claw plate 4 is arranged in a state where its downward side end face abuts against the upper surface portion 11 of the floor material 1, and is fixed to one strip plate portion of each of the main body portion 2a and the reinforcing portion 2b of the support column 2 with bolts and nuts.

[0019] And in the inspection path of this embodiment, in order to perform the state monitoring described later, a plurality of strain gauges 6 as strain measuring means are attached in a state of being arranged side by side in the width direction on the lower surface of the floor material 1 at the longitudinal center portion. Each strain gauge 6 is attached to the lower surface of the floor material 1 with an adhesive, and is covered with butyl rubber (product name: SB tape of Tokyo Sokki Co., Ltd.) and a butyl tape (product name: VM tape of Tokyo Sokki Co., Ltd.) stacked thereon so as to obtain sufficient waterproofness and electrical insulation (omitted in the drawing). Here, the attachment position of the strain gauge 6 is set to the lower surface of the floor material 1 at the longitudinal center portion of the inspection path because this portion has the highest bending stress and the largest amount of deflection.

[0020] Also, the wiring 7 connected to the strain gauge 6 enters the hollow portion from the mounting hole 15 on the lower surface of the floor material 1 and is housed in the hollow portion, and the end portion on the side opposite to the connection end with the strain gauge 6 is arranged near the opening at one end of the floor material 1.

[0021] As shown in FIG. 2, this method for monitoring the state of the inspection path is such that a worker periodically carries a dedicated hand-type data logger 8 and goes to the inspection path installation site (on-site), connects the data logger 8 to the wiring 7 pulled out from the opening at one end of the floor material 1, and records the strain value measured by the strain gauge 6 and the data of the amount of deflection calculated from the strain value in the data logger 8. The data logger 8 compares the recorded data with a preset soundness determination criterion, and determines and displays the soundness of the inspection path (which level among a plurality of levels such as sound, follow-up observation, warning, etc. the inspection path is in). Thereby, the worker can easily grasp the state of the inspection path.

[0022] While the deflection of the inspection path can also be directly measured using a dial gauge, there is a risk of the dial gauge being dropped due to weather or vibrations. Therefore, in this embodiment, the deflection is calculated from the strain value measured by the strain gauge 6. The strain gauge is lighter than the dial gauge, less likely to detach from the inspection path, and therefore safer.

[0023] Furthermore, after the workers return to an office such as a management center, away from the inspection track installation site, they can save and organize the data stored in the data logger 8 on a personal computer 9, thereby allowing them to check the changes in the condition of the inspection track over time.

[0024] The inspection path and its condition monitoring method in this embodiment have the above configuration, and based on the strain value measured by the strain gauge 6 attached to the inspection path or the amount of deflection calculated from that strain value, the condition of the inspection path can be monitored easily and quantitatively without relying on visual inspection. As a result, the remaining lifespan of the inspection path can be determined, which contributes to the efficient maintenance and management of the inspection path.

[0025] Furthermore, the wiring 7 connected to the strain gauge 6 is housed in the hollow part of the flooring material 1, so the possibility of it being damaged or cut by workers stepping on it is extremely low, allowing for continuous and normal monitoring of the inspection path.

[0026] Figure 4 shows a method for monitoring the condition of a resin inspection path according to the second embodiment. This embodiment is based on the first embodiment, but a wireless communication slave unit 21 is connected to the end of the wiring 7 of the inspection path opposite to the connection end with the strain gauge 6, and the data transmitted from this wireless communication slave unit 21 is sent to a wireless communication master unit 22 in the office via LPWA (Low Power Wide Area) communication. The received data is then processed by a personal computer 23 connected to the wireless communication master unit 22, enabling monitoring of the condition of the inspection path.

[0027] Although not shown in the diagram, if a thermocouple is attached to the flooring material 1 and its wiring is connected to the wireless communication slave unit 21, it will also be possible to remotely measure the temperature of the flooring material 1. Furthermore, if it is difficult to attach a thermocouple to the area where the temperature to be measured is to be taken, simply placing it nearby will suffice, and at least the ambient temperature will be measured.

[0028] Here, the wireless communication slave unit 21 on the inspection path side is installed in the hollow part of the floor material 1, similar to the wiring 7, taking into consideration the risk of falling due to weather conditions and the need for waterproofing. Furthermore, its installation position is near an opening at one end of the floor material 1 in order to allow the antenna 21a to be exposed to the outside.

[0029] In this second embodiment, there is no need for workers to go to the inspection track installation site (on-site), and the condition of the inspection track can be continuously monitored remotely, making the maintenance and management of the inspection track even more efficient.

[0030] In the embodiments described above, multiple strain gauges 6 were attached to the underside of the flooring material 1 in the longitudinal center of the inspection path. However, the attachment positions and number of strain gauges 6 can be arbitrarily set. For example, since strain tends to concentrate around the support frame 10 in the flooring material 1, as shown in Figure 5, strain gauges 6 can be attached to the underside of the flooring material 1 near the support frame 10 to monitor the condition of the inspection path. Furthermore, depending on the site, the number of strain gauges 6 may be limited to just one, regardless of the attachment position.

[0031] Furthermore, while the mounting holes for the flooring material are provided on the underside of the flooring material in each embodiment, they may also be provided on the top or side of the flooring material. In that case, it is desirable to route the wiring connected to the strain measuring means (strain gauge) out to the side from the mounting holes as much as possible. And, unlike in each embodiment, if the flooring material does not have a hollow section, it is desirable to mount the strain measuring means and wiring on the underside or side of the flooring material as much as possible.

[0032] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims, not in the sense described above, and all modifications within the sense and scope equivalent to the claims are intended.

[0033] For example, the strain measuring device attached to the resin inspection path is not limited to strain gauges as in each embodiment; any device that can be easily attached to the inspection path is acceptable. [Explanation of Symbols]

[0034] 1. Flooring 2 pillars 3 Handrail 6. Strain gauge (strain measuring means) 7 Wiring 8 Data Loggers 9. Personal computer 10 Support frame 15 mounting holes 21 Wireless communication slave unit 22 Wireless communication base station 23 Personal computer

Claims

1. A strain measuring device is attached to the resin inspection path, and the soundness of the resin inspection path is determined using a preset soundness determination criterion based on the strain value measured by the strain measuring device or the amount of deflection calculated from that strain value. The floor material constituting the resin inspection path is provided with a hollow section, and the wiring connected to the strain measuring means is housed in the hollow section of the floor material. A method for monitoring the condition of a resin inspection path, characterized in that the strain measuring means is attached to the underside of the flooring material, the wiring enters the hollow portion through a mounting hole in the underside of the flooring material and is housed in the hollow portion, and the end opposite to the connection end with the strain measuring means is positioned near an opening at one end of the flooring material.

2. A strain measuring means is attached to a resin inspection path, and the soundness of the resin inspection path is determined using a preset soundness determination criterion based on the strain value measured by the strain measuring means or the amount of deflection calculated from the strain value, The floor material constituting the resin inspection path is provided with a hollow section, and the wiring connected to the strain measuring means is housed in the hollow section of the floor material. A method for monitoring the condition of a resin inspection path, characterized in that the strain measuring means is attached to the underside of the floor material near the support frame on which the floor material is placed and fixed.

3. The method for monitoring the condition of a resin inspection path according to claim 1 or 2, characterized in that the strain measuring means is a strain gauge.

4. In a resin inspection walkway with a hollow section in the flooring material, a strain measuring means is attached, and wiring connected to the strain measuring means is housed in the hollow section of the flooring material. A resin inspection passage characterized in that the strain measuring means is attached to the underside of the flooring material, the wiring enters the hollow portion through a mounting hole in the underside of the flooring material and is housed in the hollow portion, and the end opposite to the connection end with the strain measuring means is positioned near an opening at one end of the flooring material.

5. In a resin inspection path having a hollow section in the flooring material, a strain measuring means is attached, and wiring connected to the strain measuring means is housed in the hollow section of the flooring material, A resin inspection walkway characterized in that the strain measuring means is attached to the underside of the flooring material near the support frame on which the flooring material is placed and fixed.

6. The resin inspection path according to claim 4 or 5, characterized in that a data transmission means for transmitting data of strain values ​​measured by the strain measuring means to the outside is connected to the wiring, and the data transmission means is installed in the hollow part of the floor material.

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