Utility pole, utility pole deterioration time estimation device, and utility pole deterioration time estimation method

Abstract

To provide a utility pole capable of suppressing deterioration.SOLUTION: A utility pole 1 has a truncated cone shape or a cylindrical shape with a central axis extending in the vertical direction. The utility pole 1 includes a body part 11 and a plurality of reinforcing bars 12. The body part 11 constitutes at least a part of the utility pole 1 other than both end parts in the vertical direction, is made of concrete, and is hollow. The plurality of reinforcing bars 12 extend in the axial direction between an inner peripheral surface IS of the main body part 11 and an outer peripheral surface OS of the main body part 11. In the utility pole 1, for each of the plurality of reinforcing bars 12, a coating thickness ratio which is a ratio of an inner coating thickness T1 which is a distance between an inner peripheral surface IS of the body part 11 and the reinforcing bar 12 to an outer coating thickness T2 which is a distance between an outer peripheral surface OS of the body part 11 and the reinforcing bar 12 is 1.2 or less.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a utility pole, a utility pole deterioration time estimation device, and a utility pole deterioration time estimation method. [Background technology]

[0002] Utility poles are known that are installed to extend vertically and support overhead lines (e.g., electric wires, telephone lines, or communication cables) in midair. For example, the utility pole described in Patent Document 1 has a truncated cone shape with a central axis extending vertically. The utility pole comprises a hollow main body that constitutes at least a portion of the utility pole other than both vertical ends, and is made of concrete. The utility pole comprises a plurality of reinforcing bars that extend axially between the inner peripheral surface of the main body and the outer peripheral surface of the main body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-345132 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, when moisture contained in wind, rain, snow, etc. adheres to the outer peripheral surface of the main body, the moisture penetrates from the outer peripheral surface into the inside of the main body. As a result, the reinforcing bars located inside the main body corrode and rust is generated. In particular, in areas near the sea, wind, rain, snow, etc. contain a relatively large amount of salt. Therefore, the salt also penetrates from the outer peripheral surface of the main body into the inside of the main body, which tends to accelerate the corrosion of the reinforcing bars and the generation of rust.

[0005] The strength of the reinforcing bar decreases with corrosion. Furthermore, rust formed inside the main body generates stress within the main body. As a result, cracks may occur in the main body. In particular, if cracks occur on the outer peripheral surface of the main body, moisture and salt are more likely to penetrate from the outer peripheral surface of the main body into the inside of the main body. Therefore, in this case, corrosion and rust formation of the reinforcing bar are more likely to be accelerated. Thus, the utility pole described in Patent Document 1 has a problem in that it may deteriorate relatively quickly.

[0006] One of the objects of the present invention is to inhibit deterioration of utility poles. [Means for solving the problem]

[0007] In one aspect, the pole is frusto-conical or cylindrical with a central axis extending vertically. The utility pole includes a main body and a plurality of reinforcing bars. The main body constitutes at least a portion of the utility pole other than both vertical ends, is made of concrete, and is hollow. The reinforcing bars extend in the axial direction between an inner peripheral surface of the main body and an outer peripheral surface of the main body.

[0008] For each of the multiple reinforcing bars of the utility pole, the coating thickness ratio, which is the ratio of the inner coating thickness, which is the distance between the inner surface of the main body and the reinforcing bar, to the outer coating thickness, which is the distance between the outer surface of the main body and the reinforcing bar, is 1.2 or less.

[0009] In another aspect, a utility pole deterioration time estimation device estimates a deterioration time that represents the time required for a utility pole that is frustum-shaped or cylindrical and has a central axis extending in a vertical direction to deteriorate. The utility pole includes a main body and a plurality of reinforcing bars. The main body constitutes at least a portion of the utility pole other than both vertical ends, is made of concrete, and is hollow. The reinforcing bars extend in the axial direction between an inner peripheral surface of the main body and an outer peripheral surface of the main body.

[0010] The utility pole deterioration time estimation device includes a coverage thickness ratio information acquisition unit and a deterioration time estimation unit. The coating thickness ratio information acquisition unit acquires, for at least one of the multiple reinforcing bars, coating thickness ratio information that represents a coating thickness ratio, which is the ratio of the inner coating thickness, which is the distance between the inner surface of the main body and the reinforcing bar, to the outer coating thickness, which is the distance between the outer surface of the main body and the reinforcing bar. The deterioration time estimation unit estimates the deterioration time of the utility pole based on the coverage thickness ratio represented by the acquired coverage thickness ratio information.

[0011] In another aspect, a utility pole deterioration time estimation method estimates a deterioration time that indicates the degree of deterioration of a utility pole that is shaped like a truncated cone or a cylinder and whose central axis extends in a vertical direction. The utility pole includes a main body and a plurality of reinforcing bars. The main body constitutes at least a portion of the utility pole other than both vertical ends, is made of concrete, and is hollow. The reinforcing bars extend in the axial direction between an inner peripheral surface of the main body and an outer peripheral surface of the main body.

[0012] The method for estimating the deterioration time of utility poles is as follows: Acquire, for at least one of the plurality of reinforcing bars, coating thickness ratio information that represents a coating thickness ratio that is a ratio of an inner coating thickness, which is the distance between an inner circumferential surface of the main body portion and the reinforcing bar, to an outer coating thickness, which is the distance between an outer circumferential surface of the main body portion and the reinforcing bar; estimating a deterioration time of the utility pole based on the coverage thickness ratio represented by the obtained coverage thickness ratio information; This includes: Effect of the Invention

[0013] This can prevent deterioration of utility poles. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is an enlarged view of a portion of a horizontal cross section of a utility pole. [Diagram 2] FIG. 1 is an explanatory diagram showing the propagation of a crack that occurred near a reinforcing bar inside a utility pole. [Diagram 3] FIG. 2 is a diagram illustrating a horizontal cross section of the utility pole of the first embodiment. [Figure 4]FIG. 4 is an enlarged view of a portion of FIG. 3. [Diagram 5] FIG. 1 is an explanatory diagram showing a configuration of an accelerated deterioration test. [Figure 6] 1 is a graph showing changes in strain over time in a utility pole as an example of the first embodiment. [Figure 7] 13 is a graph showing the change in strain over time in a utility pole of a comparative example. [Figure 8] 1 is a graph showing the change in crack initiation time for a utility pole versus outer coating thickness. [Figure 9] 1 is a graph showing the change in crack initiation time in a utility pole versus the thickness of the inner coating. [Figure 10] 1 is a graph showing the change in time to crack occurrence in a utility pole versus the coating thickness ratio. [Figure 11] FIG. 11 is a block diagram showing a configuration of a utility pole deterioration time estimation device according to a second embodiment. [Figure 12] FIG. 11 is a block diagram showing functions of a utility pole deterioration time estimation device according to a second embodiment. [Figure 13] 13 is a graph showing the relationship between the crack occurrence time and the coating thickness ratio, which is used by the utility pole deterioration time estimation device of the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, embodiments of a utility pole, a utility pole deterioration time estimating device, and a utility pole deterioration time estimating method of the present invention will be described with reference to Figs.

[0016] Fig. 1 is an enlarged view of a portion of a horizontal cross section of a utility pole. As indicated by the arrows marked with the symbol WS in Fig. 1, moisture and salt attached to the outer peripheral surface OS of a main body 91 of the utility pole penetrate from the outer peripheral surface OS of the main body 91 into the inside of the main body 91. Therefore, as indicated in Fig. 2(A), a hypothesis can be made that the outer peripheral surface OS of the main body 91 is more susceptible to corrosion and rust RU than the inner peripheral surface IS of the main body 91, and therefore a crack CR generated near the reinforcing bar 92 extends to the outer peripheral surface OS of the main body 91, and thus the outer peripheral surface OS of the main body 91 is more likely to develop cracks CR than the inner peripheral surface IS of the main body 91.

[0017] On the other hand, the main body 91 is often a centrifugal reinforced concrete pipe formed by compacting concrete using centrifugal force. In this case, the water-cement ratio (in other words, W / C), which is the ratio of the weight of water to the weight of cement in concrete, and the ratio of the volume of air contained in concrete (in other words, air ratio or air volume) tend to be low compared to when the concrete is formed by compacting it using a method other than centrifugal force (for example, vibration, etc.), so the concrete tends to be dense.

[0018] The portion of the main body 91 near the outer peripheral surface OS is formed by applying a larger centrifugal force than the portion near the inner peripheral surface IS. Therefore, the portion of the main body 91 near the outer peripheral surface OS is often denser than the portion near the inner peripheral surface IS. Therefore, as shown in FIG. 2B, it can be hypothesized that the inner peripheral surface IS of the main body 91 is more likely to develop cracks CR before the outer peripheral surface OS of the main body 91.

[0019] As described above, the relationship between the corrosion and rust formation of reinforcing bars and the occurrence of cracks in utility poles remains largely unknown. The inventors of the present application therefore conducted extensive research into this relationship and came up with the invention of the present application.

[0020] First Embodiment (overview) The utility pole of the first embodiment has a truncated cone or cylinder shape with a central axis extending in the vertical direction. The utility pole includes a main body and a plurality of reinforcing bars. The main body constitutes at least a portion of the utility pole other than both ends in the vertical direction, is made of concrete, and is hollow. The plurality of reinforcing bars extend in the axial direction between an inner peripheral surface of the main body and an outer peripheral surface of the main body. For each of the multiple reinforcing bars of the utility pole, the coating thickness ratio, which is the ratio of the inner coating thickness, which is the distance between the inner surface of the main body and the reinforcing bar, to the outer coating thickness, which is the distance between the outer surface of the main body and the reinforcing bar, is 1.2 or less.

[0021] As a result of careful investigation, the inventors of the present application have found that when a crack occurs on the inner surface of the main body before it occurs on the outer surface of the main body, cracks are less likely to occur on the outer surface of the main body, and that when the coating thickness ratio is 1.2 or less, cracks are more likely to occur on the inner surface of the main body before it occurs on the outer surface of the main body.

[0022] Therefore, according to the utility pole of the first embodiment, since cracks are likely to occur on the inner circumferential surface of the main body before they occur on the outer circumferential surface of the main body, it is possible to suppress the occurrence of cracks on the outer circumferential surface of the main body, and as a result, deterioration of the utility pole can be suppressed. Next, the utility pole of the first embodiment will be described in more detail.

[0023] (composition) As shown in Figures 3 and 4, utility pole 1 has a truncated cone shape with a central axis extending in the vertical direction. The diameter of utility pole 1 decreases in the vertically upward direction. In this example, utility pole 1 has a diameter of 150 mm to 450 mm. Utility pole 1 may also be cylindrical. Figure 3 shows a cross section of utility pole 1 cut along a horizontal plane. Figure 4 is an enlarged view of area IV surrounded by a dashed line in Figure 3.

[0024] The utility pole 1 comprises a main body 11, a plurality of (in this example, 12) axial reinforcing bars 12, circumferential reinforcing bars (not shown), a cover portion (not shown), and a bottom portion (not shown).

[0025] The main body 11 constitutes at least a part of the utility pole 1 other than the lid and the bottom that constitute both ends in the vertical direction. In this example, the main body 11 constitutes the portion of the utility pole 1 between the lid and the bottom that constitute both ends in the vertical direction. The cover portion constitutes the vertically upper end of the utility pole 1. The bottom portion constitutes the vertically lower end of the utility pole 1.

[0026] The main body 11 is made of concrete and is hollow. In this example, the main body 11 is a centrifugally reinforced concrete pipe. The centrifugally reinforced concrete pipe is formed by compacting concrete by centrifugal force. The centrifugally reinforced concrete pipe may be referred to as a Hume pipe. In this example, the distance between the inner peripheral surface IS of the main body 11 and the outer peripheral surface OS of the main body 11 (in other words, the thickness of the main body 11) is 30 mm to 80 mm.

[0027] Each axial reinforcing bar 12 extends in the axial direction of the main body portion 11 between an inner circumferential surface IS of the main body portion 11 and an outer circumferential surface OS of the main body portion 11. In this example, the multiple axial reinforcing bars 12 are positioned at approximately equal intervals in the circumferential direction of the main body portion 11. Each axial reinforcing bar 12 is a tension member or a non-tension member. For example, each axial reinforcing bar 12 is a PC (Prestressed Concrete) steel wire or a PC steel rod. In this example, the diameter of each axial reinforcing bar 12 is 7 mm to 10 mm.

[0028] Each axial reinforcing bar 12 has a coating thickness ratio of 1.2 or less. In this example, each axial reinforcing bar 12 has a coating thickness ratio of 0.4 to 1.2. Preferably, each axial reinforcing bar 12 has a coating thickness ratio of 0.4 to 0.8. 4, the coating thickness ratio is the ratio of an inner coating thickness T1, which is the distance between an inner circumferential surface IS of the main body 11 and the axial reinforcing bars 12 in the direction along the reference line RL, to an outer coating thickness T2, which is the distance between an outer circumferential surface OS of the main body 11 and the axial reinforcing bars 12 in the direction along the reference line RL. In this example, the reference line RL is a straight line passing through the central axis of the main body 11 and the central axis of the axial reinforcing bars 12 in a horizontal plane.

[0029] Each axial reinforcing bar 12 has an inner coating thickness T1 of 3 mm or more. In this example, each axial reinforcing bar 12 has an inner coating thickness T1 of 3 mm to 35 mm. Each axial reinforcing bar 12 has an inner coating thickness T1 of preferably 5 mm or more, more preferably 9 mm or more.

[0030] Each axial reinforcing bar 12 has an outer coating thickness T2 of 35 mm or less. In this example, each axial reinforcing bar 12 has an outer coating thickness T2 of 9 mm to 35 mm.

[0031] The circumferential rebar is wound around the multiple axial rebars 12 and fixed to the multiple axial rebars 12. For example, the circumferential rebar is fixed to the multiple axial rebars 12 by spot welding. In this example, the circumferential rebar is spiral and extends over the entire axial direction of the main body 11. The utility pole 1 may include multiple annular circumferential rebars. Also, the utility pole 1 does not need to include a circumferential rebar.

[0032] The utility pole 1 is installed so as to extend in the vertical direction by having its end portion in the vertically downward direction buried in the ground. In this example, an overhead line (not shown) is installed between utility pole 1 and another utility pole (not shown) other than utility pole 1. For example, the overhead line is an electric wire, a telephone line, a communication cable, etc. Utility pole 1 supports the overhead line at the end of utility pole 1 in the vertically upward direction.

[0033] As described above, the utility pole 1 of the first embodiment is in the shape of a truncated cone or a cylinder (in this example, a truncated cone) whose central axis extends in the vertical direction. The main body 11 includes the main body 11 and a plurality of reinforcing bars (in this example, axial reinforcing bars) 12. The main body 11 constitutes at least a part of the utility pole 1 other than both ends in the vertical direction, is made of concrete, and is hollow. The plurality of reinforcing bars 12 extend in the axial direction between the inner circumferential surface IS of the main body 11 and the outer circumferential surface OS of the main body 11. In the utility pole 1, for each of the plurality of axial reinforcing bars 12, a covering thickness ratio, which is a ratio of an inner covering thickness, which is a distance between the inner circumferential surface IS of the main body 11 and the reinforcing bar 12, to an outer covering thickness, which is a distance between the outer circumferential surface OS of the main body 11 and the reinforcing bar 12, is 1.2 or less.

[0034] According to this, cracks are more likely to occur on the inner circumferential surface IS of the main body 11 before they occur on the outer circumferential surface OS of the main body 11, so it is possible to suppress the occurrence of cracks on the outer circumferential surface OS of the main body 11. As a result, deterioration of the utility pole 1 can be suppressed. Furthermore, it is preferable that the coating thickness ratio is 1.1 or less. In this case, it is possible to further suppress the occurrence of cracks on the outer circumferential surface OS of the main body 11. As a result, deterioration of the utility pole 1 can be suppressed.

[0035] Furthermore, the utility pole 1 of the first embodiment has a covering thickness ratio for each of the multiple axial reinforcing bars 12 of 0.4 to 0.8.

[0036] As a result of extensive investigation, the inventors of the present application have found that when the coating thickness ratio has a value of 0.4 to 0.8, the time required for cracks to occur on the outer peripheral surface OS of the main body portion 11 tends to be long. Therefore, according to the utility pole 1 of the first embodiment, it is possible to sufficiently extend the time required for cracks to occur in the outer circumferential surface OS of the main body 11. As a result, deterioration of the utility pole 1 can be suppressed.

[0037] Furthermore, in the utility pole 1 of the first embodiment, the inner coating thickness T1 for each of the multiple axial reinforcing bars 12 has a value between 9 mm and 35 mm.

[0038] However, if the inner coating thickness is less than 9 mm, there is a risk that the bending strength of the utility pole 1 will be too low. In contrast, according to the utility pole 1 of the first embodiment, the bending strength of the utility pole 1 can be sufficiently increased.

[0039] <Example> An experiment conducted to examine the relationship between the corrosion and rust generation of the reinforcing bar 12 and the occurrence of cracks in the utility pole 1 of the example of the first embodiment will be described. In this example, as shown in FIG. 5, an accelerated deterioration test was carried out in which the reinforcing bar 12 was corroded to cause cracks to occur.

[0040] The sample SM is a part of the main body 11. The sample SM is supported vertically above the water tank WP so that the axial direction of the main body 11 is positioned horizontally. A positive terminal of a constant current power supply CC is connected to one of the reinforcing bars 12 of the sample SM.

[0041] The water tank WP stores salt water SW having a concentration of 3% by weight. A wire mesh (in this example, a wire mesh made of stainless steel) WM is immersed in salt water SW. A negative terminal of a constant current power source CC is connected to the wire mesh WM. A part of the sponge SP is immersed in salt water SW. The wire mesh WM is in contact with a portion of the outer circumferential surface OS of the sample SM that is vertically below the reinforcing bar 12 via the sponge SP.

[0042] A constant DC current is supplied from the constant current power supply CC, so that a DC current flows through the reinforcing bar 12. In this manner, corrosion of the reinforcing bar 12 and the generation of rust are promoted.

[0043] Two outer strain gauges SGO are attached to the outer peripheral surface OS of the sample SM so as to measure the strain in the circumferential direction of the sample SM. Two inner strain gauges SGI are attached to the inner peripheral surface IS of the sample SM so as to measure the strain in the circumferential direction of the sample SM. The inner strain gauges SGI and the outer strain gauges SGO face each other so as to sandwich the reinforcing bar 12 therebetween.

[0044] In this accelerated aging test, the salt penetration that occurs in a natural environment near the sea for 3,000 to 8,000 hours is achieved in about one hour.

[0045] Table 1 shows the results of the accelerated aging test for each of the samples with sample numbers 1 to 20. The samples with sample numbers 1 to 12 are parts of the utility pole 1 of the example of the first embodiment. The samples with sample numbers 13 to 20 are parts of the utility pole of the comparative example. [Table 1]

[0046] In this example, the crack initiation time is the time required (or elapsed) for the strain measured by the outer strain gauge SGO to reach 500μ. In this example, the length of each of the outer strain gauge SGO and the inner strain gauge SGI is 30 mm. Therefore, a strain of 500μ corresponds to an elongation of the outer strain gauge SGO and the inner strain gauge SGI of 15 μm.

[0047] The inward crack type indicates that a crack occurs on the inner peripheral surface of the sample before it occurs on the outer peripheral surface of the sample. On the other hand, the outward crack type indicates that a crack occurs on the outer peripheral surface of the sample before it occurs on the inner peripheral surface of the sample. When a crack occurs, the strain increases rapidly. Therefore, in this example, the crack type is determined based on the relationship between the time when the strain measured by the outer strain gauge SGO increases rapidly and the time when the strain measured by the inner strain gauge SGI increases rapidly.

[0048] Figure 6 shows the change in strain over time measured for the comparative sample, sample number 14. In Figure 6, the curve labeled CO1 represents the strain measured by the outer strain gauge SGO. In Figure 6, the curve labeled CI1 represents the strain measured by the inner strain gauge SGI.

[0049] As shown in Figure 6, the strain measured by the outer strain gauge SGO increases sharply at about 15 hours, while the strain measured by the inner strain gauge SGI increases sharply at about 20 hours. In this way, the comparative sample is an outward-first type in which cracks occur on the outer peripheral surface of the sample before they occur on the inner peripheral surface of the sample.

[0050] Figure 7 shows the change in strain over time measured for the example sample of sample number 1. In Figure 7, the curve labeled CO2 represents the strain measured by the outer strain gauge SGO. In Figure 7, the curve labeled CI2 represents the strain measured by the inner strain gauge SGI.

[0051] As shown in Figure 7, the strain measured by the inner strain gauge SGI increases sharply at about 15 hours, while the strain measured by the outer strain gauge SGO increases sharply at about 55 hours. In this way, the sample of the embodiment is an inward-first type in which cracks occur on the inner peripheral surface of the sample before they occur on the outer peripheral surface of the sample.

[0052] As shown in Figs. 6 and 7, when cracks occur on the inner circumferential surface of the main body before they occur on the outer circumferential surface of the main body, cracks are less likely to occur on the outer circumferential surface of the main body.

[0053] Figure 8 shows the change in crack initiation time versus outer coating thickness, Figure 9 shows the change in crack initiation time versus inner coating thickness, and Figure 10 shows the change in crack initiation time versus coating thickness ratio.

[0054] 10, when the coating thickness ratio is 1.2 or less, cracks tend to occur on the inner circumferential surface of the main body before they occur on the outer circumferential surface of the main body. Furthermore, when the coating thickness ratio is 1.2 or less, the smaller the coating thickness ratio is, the longer the time it takes for cracks to occur.

[0055] Furthermore, when the coating thickness ratio is 1.2 or less, the relationship between the coating thickness ratio x and the crack occurrence time y is approximated by Equation 1, as represented by the straight line marked with the symbol AL in Fig. 10. In this example, the first parameter a is -39.2, and the second parameter b is 69.8.

number

[0056] In this way, according to the utility pole 1 of the first embodiment, cracks are more likely to occur on the inner circumferential surface IS of the main body 11 before they occur on the outer circumferential surface OS of the main body 11, so it is possible to prevent cracks from occurring on the outer circumferential surface OS of the main body 11. As a result, deterioration of the utility pole 1 can be suppressed.

[0057] <Second embodiment> (overview) The utility pole deterioration time estimation device of the second embodiment estimates a deterioration time that indicates the time required for a utility pole having a truncated cone or cylinder shape with a central axis extending in the vertical direction to deteriorate. The utility pole includes a main body and a plurality of reinforcing bars. The main body constitutes at least a part of the utility pole other than both ends in the vertical direction, is made of concrete, and is hollow. The plurality of reinforcing bars extend in the axial direction between an inner peripheral surface of the main body and an outer peripheral surface of the main body.

[0058] The utility pole deterioration time estimation device includes a coverage thickness ratio information acquisition unit and a deterioration time estimation unit. The coating thickness ratio information acquisition unit acquires, for at least one of the multiple reinforcing bars, coating thickness ratio information that represents a coating thickness ratio, which is the ratio of the inner coating thickness, which is the distance between the inner surface of the main body and the reinforcing bar, to the outer coating thickness, which is the distance between the outer surface of the main body and the reinforcing bar. The deterioration time estimation unit estimates a deterioration time based on the coating thickness ratio represented by the acquired coating thickness ratio information.

[0059] Incidentally, there is a strong correlation between the deterioration time of a utility pole and the insulation thickness ratio. Therefore, the utility pole deterioration time estimation device of the second embodiment can estimate the deterioration time of a utility pole with high accuracy. Next, the utility pole deterioration time estimation device of the second embodiment will be described in more detail.

[0060] (composition) As shown in Fig. 11, the utility pole deterioration time estimation device 20 includes a processing device 21, a storage device 22, an input device 23, and an output device 24, which are connected to each other via a bus BU1. For example, the utility pole deterioration time estimation device 20 is configured by a computer (in other words, an information processing device). The computer may be a server type computer, a desktop type computer, a laptop type computer, or a tablet type computer. The computer may also be at least a part of a smartphone or the like. The utility pole deterioration time estimation device 20 may also be configured by a plurality of devices connected to each other so as to be able to communicate with each other.

[0061] The processing device 21 executes a program stored in the storage device 22 to control the storage device 22, the input device 23, and the output device 24. In this way, the processing device 21 realizes the functions described below.

[0062] In this example, the processing device 21 is a central processing unit (CPU). Note that the processing device 21 may include a micro processing unit (MPU), a graphics processing unit (GPU), or a digital signal processor (DSP) instead of or in addition to the CPU.

[0063] In this example, the storage device 22 includes a volatile memory and a non-volatile memory. For example, the storage device 22 includes at least one of a random access memory (RAM), a read only memory (ROM), a semiconductor memory, an organic memory, a hard disk drive (HDD), and a solid state drive (SSD).

[0064] The input device 23 inputs information from outside the utility pole deterioration time estimation device 20. In this example, the input device 23 includes a keyboard and a mouse. The input device 23 may also include a microphone.

[0065] The output device 24 outputs information to the outside of the utility pole deterioration time estimation device 20. In this example, the output device 24 includes a display. The output device 24 may also include a speaker. In addition, the utility pole deterioration time estimation device 20 may be equipped with a touch panel type display that constitutes both the input device 23 and the output device 24.

[0066] (function) As shown in FIG. 12 , the functions of the utility pole deterioration time estimation device 20 include an input information receiving unit 201, a coverage thickness ratio information acquisition unit 202, and a deterioration time estimation unit 203.

[0067] The input information receiving unit 201 receives the coating thickness information and the salinity information input by the user of the utility pole deterioration time estimation device 20 via the input device 23. In this example, the utility pole to be estimated is the utility pole 1 of the first embodiment. Note that the utility pole to be estimated may be the utility pole of the comparative example.

[0068] In this example, the coating thickness information includes information representing the outer coating thickness, information representing the thickness of the main body 11, and information representing the diameter of the axial reinforcing bar 12. Note that the coating thickness information may also include information representing the outer coating thickness and information representing the inner coating thickness. For example, the coating thickness information may be obtained using a non-destructive testing technique using ultrasonic waves or electromagnetic waves.

[0069] In this example, the salt information represents the amount of salt present in the natural environment in the area where the utility pole 1 is installed. For example, the salinity information represents the level of the amount of salt (e.g., high or low, etc.). For example, the salt present in the natural environment includes salt contained in the wind (in other words, airborne salt). Note that the salt present in the natural environment may also include salt attached to the surface of the utility pole 1 (in other words, attached salt). Furthermore, the salt present in the natural environment may also include salt contained in rain, snow, etc.

[0070] For example, the amount of airborne salt may be measured using the dry gauze method defined in JIS (Japanese Industrial Standards) Z 2382, or the wet candle method defined in ISO (International Organization for Standardization) 9225. Furthermore, for example, the amount of deposited salt may be measured using a method for measuring equivalent salt deposit density (ESDD) (e.g., a brush washing method, etc.), or using a handheld X-ray fluorescence analyzer, etc.

[0071] The coating thickness ratio information acquisition unit 202 acquires the coating thickness ratio information based on the coating thickness information received by the input information reception unit 201. The coating thickness ratio information indicates a coating thickness ratio. In this example, the coating thickness ratio information acquisition unit 202 calculates a value obtained by subtracting the sum of the outer coating thickness and the diameter of the axial reinforcing bar 12 from the thickness of the main body 11 (in other words, the inner coating thickness) and dividing the result by the outer coating thickness as the coating thickness ratio.

[0072] The deterioration time estimation unit 203 estimates the deterioration time of the utility pole 1 based on the covering thickness ratio represented by the covering thickness ratio information acquired by the covering thickness ratio information acquisition unit 202. In this example, the deterioration time represents the time required for a crack to occur on the outer circumferential surface OS of the main body portion 11.

[0073] In this example, when the covering thickness ratio is equal to or smaller than a predetermined threshold, the deterioration time estimation unit 203 estimates the deterioration time of the utility pole 1 so that the deterioration time has a value that increases as the covering thickness ratio decreases. In this example, the threshold is 1.2. The threshold may be a value between 0.8 and 1.2. Furthermore, in this example, when the coverage thickness ratio is greater than the threshold value, the deterioration time estimation unit 203 estimates the deterioration time of the utility pole 1 so as to have a constant value.

[0074] In addition, in this example, the deterioration time estimation unit 203 estimates the deterioration time of the utility pole 1 based on the salt information received by the input information receiving unit 201 so that the deterioration time has a value that becomes shorter as the amount of salt present in the natural environment in the area where the utility pole 1 is installed increases. For example, when the covering thickness ratio is equal to or less than a threshold value, the deterioration time estimation unit 203 estimates the deterioration time of the utility pole 1 based on Equation 2 that expresses the relationship between the covering thickness ratio x and the crack occurrence time y. The first parameter a and the second parameter b are set in advance. The third parameter c has a value that becomes smaller as the amount of salt present in the natural environment in the area where the utility pole 1 is installed increases.

number

[0075] For example, as shown in FIG. 13, when the salt content is relatively low, the deterioration time estimation unit 203 estimates the deterioration time of utility pole 1 in accordance with the relationship represented by the curve marked with the symbol L1, and when the salt content is relatively high, the deterioration time estimation unit 203 estimates the deterioration time of utility pole 1 in accordance with the relationship represented by the curve marked with the symbol L2.

[0076] When the covering thickness ratio is equal to or smaller than the threshold value, the deterioration time estimation unit 203 may estimate the deterioration time of the utility pole 1 based on Equation 3 which expresses the relationship between the covering thickness ratio x and the crack occurrence time y.

number

[0077] The deterioration time estimation unit 203 may estimate the deterioration time of the utility pole 1 without being based on salt present in the natural environment in the area where the utility pole 1 is installed.

[0078] (operation) Next, the operation of the utility pole deterioration time estimation device 20 of the second embodiment will be described. First, the utility pole deterioration time estimation device 20 receives the coating thickness information and the salinity information inputted by the user of the utility pole deterioration time estimation device 20 via the input device 23. Next, the utility pole deterioration time estimation device 20 acquires coverage thickness ratio information based on the received coverage thickness information. Next, the utility pole deterioration time estimation device 20 estimates the deterioration time of the utility pole 1 based on the covering thickness ratio represented by the acquired covering thickness ratio information and the received salinity information.

[0079] As described above, the utility pole deterioration time estimation device 20 of the second embodiment estimates a deterioration time that indicates the time required for a utility pole having a truncated cone shape or a cylindrical shape with a central axis extending in the vertical direction to deteriorate. The utility pole includes a main body and a plurality of reinforcing bars. The main body constitutes at least a part of the utility pole other than both ends in the vertical direction, is made of concrete, and is hollow. The multiple reinforcing bars extend in the axial direction between the inner peripheral surface of the main body and the outer peripheral surface of the main body.

[0080] The utility pole deterioration time estimation device 20 includes a coverage thickness ratio information acquisition unit 202 and a deterioration time estimation unit 203. The coating thickness ratio information acquisition unit 202 acquires coating thickness ratio information representing a coating thickness ratio, which is the ratio of the inner coating thickness, which is the distance between the inner surface of the main body and the reinforcing bar, to the outer coating thickness, which is the distance between the outer surface of the main body and the reinforcing bar, for at least one of the multiple reinforcing bars. The deterioration time estimation unit 203 estimates the deterioration time of the utility pole based on the coverage thickness ratio represented by the obtained coverage thickness ratio information.

[0081] Incidentally, there is a strong correlation between the deterioration time of a utility pole and the insulation thickness ratio. Therefore, the utility pole deterioration time estimation device 20 can estimate the deterioration time of a utility pole with high accuracy.

[0082] Furthermore, in the utility pole deterioration time estimation device 20 of the second embodiment, the deterioration time represents the time required for a crack to occur on the outer circumferential surface of the main body. When the covering thickness ratio is equal to or smaller than a predetermined threshold, the deterioration time estimation unit 203 estimates the deterioration time of the utility pole to have a value that increases as the covering thickness ratio decreases.

[0083] Incidentally, there is a strong correlation between the time required for cracks to occur on the outer peripheral surface of the main body and the coating thickness ratio. Furthermore, when the coating thickness ratio is equal to or less than a predetermined threshold, the time required for cracks to occur on the outer peripheral surface of the main body tends to be longer as the coating thickness ratio decreases. Therefore, the utility pole deterioration time estimation device 20 can estimate the deterioration time of the utility pole with high accuracy.

[0084] The utility pole deterioration time estimation device 20 may include a communication device that communicates with a device external to the utility pole deterioration time estimation device 20. The communication device performs communication according to a predetermined communication standard. For example, the communication standard is a standard related to wireless LAN (Local Area Network) (e.g., IEEE (Institute of Electrical and Electronics Engineers) 802.11) or a standard related to short-range wireless communication (e.g., Bluetooth (registered trademark)).

[0085] In this case, the input information receiving unit 201 may receive the coating thickness information transmitted by the device that acquires the coating thickness information via the communication device. Also, the input information receiving unit 201 may receive the salinity information transmitted by the device that acquires the salinity information via the communication device.

[0086] The present invention is not limited to the above-described embodiment. For example, various modifications that can be understood by a person skilled in the art may be made to the above-described embodiment without departing from the spirit of the present invention. [Explanation of symbols]

[0087] 1. Electric pole 11 Main body 12 Reinforcement 20. Utility pole deterioration time estimation device 21 Processing equipment 22 Storage device 23 Input Devices 24 Output Devices 201 Input information reception unit 202 Covering thickness ratio information acquisition section 203 Deterioration Time Estimation Unit 91 Main body 92 Reinforcement BU1 Bus CC constant current power supply IS inner surface OS outer surface SGI inner strain gauge SGO Outer Strain Gauge SM sample SP Sponge SW Saltwater WM Wire Mesh WP Aquarium

Claims

1. A utility pole having a truncated cone or cylinder shape with a central axis extending in a vertical direction, A main body portion that constitutes at least a portion of the utility pole other than both ends in the vertical direction and is made of concrete and hollow; A plurality of reinforcing bars extending in an axial direction between an inner circumferential surface of the main body and an outer circumferential surface of the main body, A centrifugal reinforced concrete pipe is formed by compacting concrete by centrifugal force so that a portion near an outer circumferential surface of the body portion is denser than a portion near an inner circumferential surface of the body portion, a coating thickness ratio, which is a ratio of an inner coating thickness, which is the distance between the inner circumferential surface and the reinforcing bar, to an outer coating thickness, which is the distance between the outer circumferential surface and the reinforcing bar, for each of the plurality of reinforcing bars, has a value of 0.4 to 1.

2.

2. 2. The utility pole according to claim 1, A utility pole, wherein the coating thickness ratio has a value of 0.4 to 0.

8.

3. The utility pole according to claim 1 or 2, The inner coating thickness has a value between 9 mm and 35 mm.

4. A utility pole deterioration time estimation device that estimates a deterioration time that represents a time required for a utility pole having a truncated cone shape or a cylindrical shape with a central axis extending in a vertical direction to deteriorate, comprising: The utility pole is A main body portion that constitutes at least a portion of the utility pole other than both ends in the vertical direction and is made of concrete and hollow; A plurality of reinforcing bars extending in an axial direction between an inner circumferential surface of the main body and an outer circumferential surface of the main body, The utility pole deterioration time estimation device comprises: A coating thickness ratio information acquisition unit that acquires coating thickness ratio information representing a coating thickness ratio, which is a ratio of an inner coating thickness, which is the distance between the inner circumferential surface and the reinforcing bar, to an outer coating thickness, which is the distance between the outer circumferential surface and the reinforcing bar, for at least one of the plurality of reinforcing bars; a deterioration time estimation unit that estimates the deterioration time based on a coating thickness ratio represented by the acquired coating thickness ratio information; A utility pole deterioration time estimation device comprising:

5. The utility pole deterioration time estimation device according to claim 4, The deterioration time represents the time required for cracks to occur on the outer circumferential surface, The deterioration time estimation unit estimates the deterioration time so that the deterioration time has a value that increases as the covering thickness ratio decreases when the covering thickness ratio is equal to or smaller than a predetermined threshold.

6. A utility pole deterioration time estimation method for estimating a deterioration time representing a degree of deterioration of a utility pole having a truncated cone shape or a cylindrical shape with a central axis extending in a vertical direction, comprising: The utility pole is A main body portion that constitutes at least a portion of the utility pole other than both ends in the vertical direction and is made of concrete and hollow; A plurality of reinforcing bars extending in an axial direction between an inner circumferential surface of the main body and an outer circumferential surface of the main body, The utility pole deterioration time estimation method includes: Acquire coating thickness ratio information representing a coating thickness ratio, which is a ratio of an inner coating thickness, which is the distance between the inner circumferential surface and the reinforcing bar, to an outer coating thickness, which is the distance between the outer circumferential surface and the reinforcing bar, for at least one of the plurality of reinforcing bars; estimating the deterioration time based on the coating thickness ratio represented by the acquired coating thickness ratio information; A method for estimating deterioration time of a utility pole, comprising:

Images