JP4471872B2 - How to determine the soundness of telephone poles or telephone poles - Google Patents

Description

  The present invention relates to a method for determining the degree of soundness of a telephone pole or telephone pole.

  The deterioration of telephone poles or telephone poles is caused by the internal structure softening or breaking due to corrosion of reinforcing bars, alkali-aggregate reaction, frost damage, etc. That is, it is desirable to be able to determine the degree of soundness.

  The method of determining the degree of soundness includes measurement by so-called destructive inspection in which pores are opened in the object and the inside is directly observed, or a part of the object is collected and analyzed, but the object is damaged. It is desirable to make a determination based on a nondestructive inspection that can be inspected without failure.

Non-destructive inspection is known to include ultrasonic flaw detection where the reflected wave is measured by injecting ultrasonic waves into the object, but the object is vibrated by, for example, striking it and comparing the resulting natural frequencies. In recent years, a so-called impact vibration test for determining the soundness is often used, and the following are known.
(Non-Patent Document 1).
Nishimura, Tanamura "Study on soundness judgment method of general bridge pier", Railway Research Institute report, Railway Technical Research Institute, August 1989, Vol. 3, No. 8, p41-49

However, electric poles and telephone poles are provided with electric wires and telephone lines at the upper ends, and the binding force generated at the upper ends varies greatly depending on the individual electric poles and telephone poles.
For this reason, the natural frequencies cannot be simply compared, and it has been necessary to create a vibration model that takes into account the differences in the individual restraining forces.

  This invention is made | formed in view of such a problem, The objective is to provide the determination method of the soundness which can determine soundness easily.

In order to achieve the above-described object, the present invention includes a step (a) of restraining the vicinity of the upper end of a power pole or telephone pole, a step (b) of striking and vibrating the power pole or the telephone pole, (C) measuring the natural frequency when the telephone pole is vibrated, and (d) determining the soundness of the telephone pole or the telephone pole based on the natural frequency. This is a method for judging the soundness of a telephone pole or telephone pole.
In the step (a), the upper end of the telephone pole or the telephone pole may be restrained by sandwiching the upper end of the telephone pole or the telephone pole from the ground, or a heavy object may be bound to the telephone pole or the telephone pole. The upper end of the telephone pole or the telephone pole may be constrained by the weight of the heavy object.
In the step (b), the electric pole or the telephone pole may be hit with a hammer, or the electric pole or the telephone pole may be hit with a weight.
The step (c) includes a step of measuring a response waveform of displacement, velocity or acceleration when the power pole or the telephone pole is vibrated, a step of obtaining a Fourier spectrum and a phase difference spectrum of the response waveform, and the Fourier Measuring the natural frequency from the spectrum and the phase difference spectrum.
In the step (d), the soundness is determined by comparing the natural frequency with a standard natural frequency.

  In the present invention, a step of restraining the vicinity of the upper end of the telephone pole or telephone pole is provided, and a vibration test is performed under restraint conditions.

  According to the present invention, since the step of restraining the vicinity of the upper end of the telephone pole or telephone pole is provided, the soundness level can be easily determined.

DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail based on the drawings. FIG. 1 is a diagram illustrating a configuration of a measurement system 1 according to the first embodiment.
2 is a perspective view of the vicinity of the restraining portion 7 in FIG. 1, and FIG. 3 is a view in the direction of arrow A in FIG.

The utility pole 2 is provided vertically or obliquely with respect to the ground 3, and electric wires 5 a and 5 b are provided at the upper end of the utility pole 2.
The aerial work vehicle 11 has an arm portion 9, and a restraint portion 7 is provided at an end portion of the arm portion 9.
Near the upper end of the utility pole 2 and the lower portions of the electric wires 5 a and 5 b are restrained by the restraining portion 7.
The aerial work vehicle 11 is provided with an outrigger 13 for fixing the vehicle to the ground.

  On the other hand, the electric pole 2 is provided with a speedometer 15, and the speedometer 15 is connected to a measurement computer 19 via a cable 17.

A hammer 21 is used when hitting the utility pole 2, and the operator 23 hits the utility pole 2 directly.
However, you may strike using a robot etc. separately.

Here, the restraint part 7 will be described in detail.
As shown in FIGS. 2 and 3, the restraining portion 7 includes semi-cylindrical curved plates 25a and 25b and a hinge 24 connected to one end of the curved plates 25a and 25b. The curved plate 25a is an actuator (not shown) or the like. Can be rotated in the B and C directions in FIG.
The curved plate 25b can be rotated in the D and E directions in FIG. 3 by driving an actuator (not shown) or the like.

That is, in FIG. 3, the utility pole 2 can be constrained by the curved plate 25a and the curved plate 25b by rotating the curved plate 25a in the B direction and rotating the curved plate 25b in the D direction.
In addition, rubber | gum, an air cushion, etc. may be provided in the surface of the curved plate 25a and the curved plate 25b so that the utility pole 2 may not be damaged.

Next, the measurement procedure will be described.
FIG. 4 is a flowchart illustrating the procedure of the soundness determination method according to the first embodiment, and FIG. 5 is a schematic diagram illustrating the impact on the utility pole 2.
6 is a vibration model of the utility pole 2, FIG. 7 is an example of a Fourier spectrum, and FIG. 8 is an example of a phase difference spectrum.

  First, the worker 23 attaches the speedometer 15 to the utility pole 2 (step 101). As described above, a displacement meter, an accelerometer, or the like may be attached instead of the speedometer.

Next, the worker 23 restrains the upper end of the utility pole by the restraint part 7 using the aerial work vehicle 11 (step 102).
At this time, the aerial work vehicle 11 is fixed to the ground 3 by using the outrigger 13 so as not to move the aerial work vehicle 11 itself.

Strictly speaking, the restraining position of the restraining portion 7 restrains the upper end of the utility pole 2 and below the place where the electric wires 5a and 5b are stretched.
This is because the portion above the place where the restraint portion 7 is restrained cannot be evaluated for soundness, but if the upper portion is restrained from the wires 5a and 5b, the influence of the tension of the wires 5a and 5b may not be removed. is there.

  Thereafter, the operator 23 and the measurement computer 19 repeat the measurement step 104 to step 106 a predetermined number of times (step 103 and step 107). The specified number of times is, for example, 10 times.

The operator 23 hits the vicinity of the center of the utility pole 2 with the hammer 21 (step 104).
Specifically, as shown in FIG. 5, the worker 23 strikes the utility pole 2 with the hammer 21.
In addition, it is desirable that the hit location is constant and near the center of the utility pole 2.
This is because the vibration mode may change if the place where the ball is hit differs.

The speedometer 15 measures the vibration speed of the utility pole 2, and the measurement computer 19 measures the response waveform of the speed (change in vibration speed with time) based on the vibration speed measured by the speedometer 15 (step 105).
The measurement computer 19 records the measured response waveform (step 106).

  The measuring computer 19 superimposes the measured response waveforms into one waveform (step 108). This is because the amplitude of the waveform is small only with the individual response waveforms, and the influence of noise may appear greatly.

The measuring computer 19 obtains the Fourier spectrum of the superimposed waveform (step 109).
Specifically, a Fourier spectrum indicating the relationship between the frequency and the amplitude as shown in FIG. 7 is obtained.

  The measurement computer 19 obtains a phase difference spectrum of the superimposed waveform (step 110). Specifically, a phase difference spectrum indicating the relationship between the frequency and the phase difference as shown in FIG. 8 is obtained.

The measuring computer 19 measures the natural frequency from the Fourier spectrum and the phase difference spectrum (step 111).
Specifically, as shown in FIG. 7 and FIG. 8, the frequency that shows the peak 30 in the Fourier spectrum and shows the specified phase difference 38 on the phase difference spectrum is extracted as the natural frequency 32.
The prescribed phase difference 38 is 0 °, 180 °, 360 ° in the case of the velocity phase difference spectrum, and 90 °, 270 ° in the case of the phase difference spectrum of the displacement and acceleration.

The measuring computer 19 calculates a soundness index from the natural frequency 32 and the standard natural frequency (step 112).
The soundness index is an index indicating the soundness of the utility pole 2 and is calculated by the following formula.
Soundness index = natural frequency / standard natural frequency

The standard natural frequency is a measure of the natural frequency of a healthy power pole. If there is data on the natural frequency of a healthy power pole such as a new one, it may be used as is. When there is no data, a value statistically calculated from data of natural frequencies measured in the past is used.
That is, based on the data of the natural frequency measured in the past and the data such as the height and weight of the utility pole, the relational expression of the height, weight and natural frequency is statistically obtained, and the height of the utility pole, If the weight is known, the standard natural frequency can be obtained.

The measurement computer 19 determines whether the soundness index is below a certain value (step 113). If the soundness index is below the certain value, the utility pole 2 is judged to be in an unhealthy state (step 114). The telephone pole 2 is determined to be in a healthy state (step 115).
This is because generally unhealthy utility poles often have low natural frequencies (small health index).

  In the first embodiment, since the test is performed with the upper end of the utility pole 2 fixed, the vibration model when hitting the utility pole 2 is fixed in both ends as shown in FIG. It becomes a simple primary vibration that vibrates. Therefore, it is not necessary to create a vibration model that takes into account the influence of the electric wires 5a and 5b.

Thus, according to 1st Embodiment, the vicinity of the upper end of the utility pole 2 is restrained using the restraint part 7, and a striking vibration test is performed in a state where both ends are fixed.
Therefore, it is not necessary to create a vibration model for each utility pole 2, and the soundness level can be easily determined.

Next, a second embodiment will be described. FIG. 9 is a diagram illustrating a configuration of the measurement system 28 according to the second embodiment.
In addition, the same number is attached | subjected to the element which performs the same function as 1st Embodiment, and description is abbreviate | omitted.

  As shown in FIG. 9, in the second embodiment, the weight 29 is placed on the utility pole 2, and the upper end of the utility pole 2 is restrained by the weight of the weight 29.

Note that the measurement procedure after restraint is the same as that in the first embodiment, and a description thereof will be omitted.
As described above, according to the second embodiment, the upper end of the utility pole 2 is restrained by the weight of the weight 29, and the impact vibration test is performed in a state where both ends are fixed.
Accordingly, the same effects as those of the first embodiment are obtained.

  Next, a third embodiment will be described. FIG. 10 is a diagram illustrating a configuration of a measurement system 34 according to the third embodiment.

  In the third embodiment, the utility pole 2 is hit using the weight 33.

As shown in FIG. 10, the measurement system 34 further uses an aerial work vehicle 11a as compared with the measurement system 1 shown in FIG.
The aerial work vehicle 11a is provided with an arm portion 9b, and a wire 31 is provided at one end of the arm portion 9b. The aerial work vehicle 11a is provided with an outrigger 13b for fixing the vehicle to the ground.
A weight 33 is provided at one end of the wire 31.

  When hitting the utility pole 2, the weight 33 is rotated by rotating it in the H direction and hitting the utility pole 2.

  Note that the measurement procedure is the same as that of the first embodiment, and a description thereof will be omitted.

Thus, according to the third embodiment, the striking vibration test is performed by constraining the vicinity of the upper end of the utility pole 2 using the restraining portion 7 and causing the weight 33 to collide with the utility pole 2 in a state where both ends are fixed.
Accordingly, the same effects as those of the first embodiment are obtained.

  Next, a fourth embodiment will be described. FIG. 11 is a diagram illustrating a configuration of a measurement system 36 according to the fourth embodiment.

  In the fourth embodiment, as in the third embodiment, the utility pole 2 is hit using the weight 33a, but the restraint and hitting are performed by the single aerial work vehicle 11.

As shown in FIG. 11, an aerial work vehicle 11 is used in the measurement system 36, and the aerial work vehicle 11 has an arm portion 9.
A wire 31a is provided on the arm 9 of the aerial work vehicle 11, and a weight 33a is provided at the tip of the wire 31a.

  When hitting the power pole 2, the weight 33 a is rotated in the I direction and hit by hitting the power pole 2.

  Note that the measurement procedure is the same as that of the first embodiment, and a description thereof will be omitted.

As described above, according to the fourth embodiment, the striking vibration test is performed by restraining the vicinity of the upper end of the utility pole 2 using the restraining portion 7 and causing the weight 33a to collide with the utility pole 2 in a state where both ends are fixed.
Accordingly, the same effects as those of the first embodiment are obtained.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

  For example, in each embodiment, the measurement computer 19 performs extraction of the natural frequency, determination of soundness, and the like, but the operator 23 may perform it.

The figure which shows the structure of the measurement system 1 1 is a perspective view of the vicinity of the restraint portion 7 in FIG. A direction arrow view of FIG. Flow chart showing the procedure of soundness determination method Schematic showing the impact on the utility pole 2 Vibration model of utility pole 2 An example of Fourier spectrum Example of phase difference spectrum The figure which shows the structure of the measurement system 28 The figure which shows the structure of the measurement system 34 The figure which shows the structure of the measurement system 36

Explanation of symbols

1 ………… Measuring system 2 ………… Pole 3 ………… Ground 5a ……… Electric wire 7 ………… Restraining part 9 ………… Arm part 11 ……… High altitude work vehicle 13 ………… Outrigger 15 ... Speedometer 17 ... Cable 19 ... Measurement computer 21 ... Hammer 23 ... Worker 24 ... Hinge 25a ... Curved plate 28 ... Measurement system 29 ... Weight 31 ......... Wire 33 ......... Weight 33a ... Weight 34 ......... Measurement system 36 ......... Measurement system

Claims (7)

A step (a) of restraining the vicinity of the upper end of the telephone pole or telephone pole;
Hitting and vibrating the utility pole or the telephone pole (b);
Measuring the natural frequency when the telephone pole or telephone pole is vibrated (c);
A step (d) of determining the soundness of the telephone pole or the telephone pole based on the natural frequency;
A method for determining the degree of soundness of a telephone pole or telephone pole, characterized by comprising: The step (a)
The soundness determination method according to claim 1, wherein the upper end of the telephone pole or the telephone pole is restrained by sandwiching the upper end of the telephone pole or the telephone pole with a member from the ground. The step (a)
The soundness determination method according to claim 1, wherein a heavy object is placed on an upper end of the electric pole or the telephone pole, and an upper end of the electric pole or the telephone pole is constrained by the weight of the heavy article.   The soundness determination method according to claim 1, wherein the step (b) hits the telephone pole or the telephone pole with a hammer.   The soundness determination method according to claim 1, wherein the step (b) hits the power pole or the telephone pole with a weight. The step (c)
Measuring a response waveform of displacement, speed, or acceleration when vibrating the telephone pole or the telephone pole;
Obtaining a Fourier spectrum and a phase difference spectrum of the response waveform;
Measuring the natural frequency from the Fourier spectrum and phase difference spectrum;
The soundness determination method according to claim 1, further comprising: The step (d)
The soundness determination method according to claim 1, wherein soundness is determined by comparing the natural frequency with a standard natural frequency.

Images