JP2011203062A - Method and apparatus for exploring buried pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for exploring for a buried pipe, which are applicable regardless of a kind of a pipe material and capable of simply identifying a buried location.SOLUTION: The method of exploring for a buried pipe identifies a location of a pipe 10 buried under the ground. While vibration is applied to an exposed part of the pipe 10, vibration of the ground is measured at a plurality of measurement points 12A, B, C and D, and vibrations at the respective measurement points 12A, B, C and D are compared with one another to identify the location of a buried part of the pipe 10.

Description

  The present invention relates to a buried pipe exploration method and apparatus.

  As a technique for confirming the state of the buried pipe, there is a technique for confirming the presence / absence of connection based on the presence / absence of hammer sound propagating in the pipe (for example, refer to Patent Document 1), or a wave signal transmitted from the ground surface. One that identifies the position by capturing the reflection (for example, see Patent Document 2), one that propagates sound waves from the end of the open branch pipe, vibrates the buried pipe, and detects this on the ground surface (for example, a patent) Reference 3).

JP 2002-365371 A JP 2001-116836 A JP 2005-308445 A

  The method for exploring buried piping using electromagnetic induction cannot be applied to exploring resinous piping that does not have electrical conductivity. In the case of a method for exploring buried pipes using sound waves propagated in the pipe, it can be applied to pipes that do not have electrical conductivity, but the end of the branch pipe must be opened. Therefore, it is necessary to isolate the pipe and exhaust the gas and liquid in the pipe in advance, which is difficult to work.

  This invention is made | formed in view of such a subject, and makes it a subject to provide the buried piping exploration method and apparatus which can be applied regardless of the material of piping and can specify a buried location easily.

  In order to solve the above problems, the present invention compares the vibration of the ground when a vibration is applied to the piping at a plurality of measurement points, and specifies the position of the buried portion of the piping.

  Specifically, it is a buried pipe exploration method for specifying the position of a pipe buried in the ground, and in a state where vibration is applied to the exposed portion of the pipe, the vibration of the ground is measured at a plurality of measurement points, The vibration of each measurement point is compared to identify the position of the buried portion of the pipe.

  Here, the exposed part of the pipe is a part that can apply vibration to the pipe by being exposed from the ground.For example, the surface of the pipe is raised by standing on the ground among the buried pipes. It is the part that is exposed to the outside. In addition, the buried part of the pipe is a part where the buried part cannot be visually identified because it is buried in the ground. For example, the pipe is buried on the road from the pipe to the site adjacent to the road. It is a part that extends.

The buried pipe exploration method applies vibration to the exposed part of such a pipe. Thereby, the vibration transmitted from the exposed portion of the pipe is transmitted to the underground pipe. The vibration transmitted to the underground pipe is also transmitted to the ground above the pipe. Therefore, the buried pipe exploration method measures the vibration of the ground at a plurality of measurement points and compares the vibrations at the respective measurement points. Since the measured value of the measured vibration shows a significant value in the portion close to the pipe compared to the far portion, the position of the buried portion of the pipe can be specified by comparing the vibration at each measurement point. According to this buried pipe exploration method, since the position of the buried portion of the pipe is identified by capturing the vibration of the ground when the pipe is vibrated, it can be applied regardless of the material of the pipe and the buried position can be easily identified. .

  The vibration applied to the exposed portion of the pipe is vibration of a specific frequency, and when specifying the position of the pipe, the vibration of the specific frequency is compared among the vibrations of each measurement point. The position of the embedded portion may be specified.

  The vibration of the ground measured at each measurement point may include many noise components such as vibration generated in the vicinity in addition to the vibration applied to the pipe. Therefore, if the vibration applied to the pipe is set as a specific frequency and the vibration of the same frequency as the specific frequency among the vibrations measured at each measurement point is compared, the pipe can be searched even if there is a noise component. it can.

  Further, the buried pipe exploration method is suitable for specifying a drawing position of a branch pipe branched from a main pipe buried in a road and drawn into a site adjacent to the road, and the vibration of the ground is detected. When measuring, the vibration of the ground between the exposed portion of the branch pipe and the road is measured at a plurality of measurement points arranged substantially along the road, and when specifying the position of the branch pipe, It is also possible to identify the pull-in position of the branch pipe by comparing the vibration at each measurement point.

  A branch pipe that is branched and drawn from a main pipe embedded in a road is usually drawn so as to be substantially orthogonal to the road, and the end of the branch pipe is often exposed in the site of the drawing destination. Therefore, it goes without saying that it is suitable for using the above-described buried pipe exploration method, and pipes buried in a wide site may be specified.

  The present invention can also be understood from the aspect of the device. For example, the invention of the present application is an embedded pipe exploration device that specifies the position of a pipe buried in the ground, and a vibration means that applies vibration to an exposed portion of the pipe, and the vibration means vibrates the pipe. A vibration measuring means for measuring ground vibration at a plurality of measurement points, and a display means for displaying the vibrations of the measurement points measured by the vibration measuring means side by side so that they can be compared. It may be.

  It can be applied regardless of the material of the pipe, and the buried portion can be easily identified.

It is a block diagram of a buried piping exploration device. It is a block diagram of a sensor array. It is the figure which looked at the installation state of a buried piping exploration device from the top. It is a block diagram of a pipe shaker. It is a block diagram of a vibration amplifier. It is a block diagram of a waveform monitor. It is an example of the waveform displayed on a monitor. It is the figure which showed the relationship between the distance of piping and each measurement point. It is a block diagram of the sensor array which concerns on a modification.

Hereinafter, embodiments of the present invention will be described. FIG. 1 is a configuration diagram of an embedded piping exploration device 1 according to the embodiment. As shown in FIG. 1, the buried pipe exploration device 1 includes a pipe vibrator 2, a vibration amplifier 3, a sensor array 4, and a waveform monitor 5. As shown in FIG. 1, the buried pipe exploration device 1 specifies a drawing position of a gas branch pipe 10 drawn from a gas main pipe 7 buried in a road 6 to a site 9 where a house 8 is built. is there. The pipe shaker 2 is attached to, for example, an exposed portion on the lower side of the gas meter 11 that is a rising portion of the branch pipe 10. The buried pipe exploration device 1 identifies not only the position of the buried portion of such a gas pipe, but also the position of a pipe for flowing other types of fluid and a pipe for passing an electric wire. It can also be used.

  FIG. 2 is a configuration diagram of the sensor array 4. As shown in FIG. 2, the sensor array 4 includes four acceleration sensors 12A, B, C, and D, rod-like fixed stays 13 and fixed stays 13 in which the acceleration sensors 12A, B, C, and D are fixed at equal intervals. The handle 14 is attached to the central portion of the sensor array 4 so that the sensor array 4 can be hand-carried. The acceleration sensors 12A, B, C, and D only need to be able to capture at least the acceleration about one axis in the vertical direction. The acceleration sensors 12A, B, C, and D are installed so as to be in contact with the ground, thereby measuring the vibration of the ground. If the measured acceleration is integrated, the speed and displacement can be specified. The acceleration sensors 12A, B, C, and D are desirably highly sensitive in order to detect propagation vibrations on the ground. For example, a servo acceleration sensor or a highly sensitive piezoelectric acceleration sensor is suitable. A speed sensor may be used instead of the acceleration sensor. As the speed sensor, for example, a geophysical sensor such as a geophone is suitable. The sensor array 4 configured as described above is light and inexpensive because the structure is extremely simple.

  By the way, each acceleration sensor 12A, B, C, D needs to be in close contact with the ground. Therefore, the fixed stay 13 is deformed by the weight of each acceleration sensor 12A, B, C, D while having a certain degree of rigidity and elasticity. Each acceleration sensor 12 is connected to the waveform monitor 5 by a signal cable 15. The interval between the acceleration sensors 12 is appropriately determined according to the depth and thickness of the pipe to be searched, the magnitude of vibration applied to the pipe by the pipe shaker 2, etc. In this embodiment, it is approximately 300 mm. ing. A buffer material may be sandwiched between the fixed stay 13 and each of the acceleration sensors 12A, B, C, and D so that vibrations are not transmitted between the acceleration sensors 12A, B, C, and D.

  FIG. 3 is a view of the installation state of the buried pipe exploration device 1 as seen from above. As shown in FIG. 3, the gas branch pipe 10 drawn into the site 9 is usually drawn from the main pipe 7 embedded in the road 6 into the site 9 in a direction substantially orthogonal to the road 6. Therefore, if the measurement points for measuring the vibration of the ground are determined so as to be arranged along the road 6, the amplitude of the vibration measured at each measurement point will be different, and the branch pipe 10 is drawn into any location. It can be specified. In the sensor array 4, four acceleration sensors 12 A, B, C, and D are arranged on a straight line by a fixed stay 13 so that measurement points for measuring ground vibration are arranged along the road 6 in this way. .

FIG. 4 is a configuration diagram of the pipe vibrator 2. As shown in FIG. 4, the pipe vibration exciter 2 includes an attaching jig 16A, B, a vertical pipe clamping bolt 17 that fastens the attaching jigs 16A, 16B, and a contact 18 that contacts the branch pipe 10. A vibration actuator 19 and a fastening bolt 20 that sandwiches the branch pipe 10 in cooperation with the vibration actuator 19 are provided. The vibration actuator 19 is a giant magnetostrictive element that vibrates the contact 18 by a giant magnetostrictive material arranged inside the coil when a sinusoidal current output from the excitation amplifier 3 flows through the coil. Excellent responsiveness to stress and generated stress. For this reason, by inputting a specific frequency (excitation frequency) generated by the excitation amplifier 3 to the excitation actuator 19, for example, a sine wave having a good vibration transmission efficiency of 100 to 1000 Hz, the branch pipe 10 is sufficiently provided. Can be vibrated. In the present embodiment, a sound wave or the like is not flowed into the cavity in the branch pipe 10, but a method of searching by vibrating the branch pipe 10 itself is employed. The vibration transmitted to the branch pipe 10 is attenuated immediately in the ground. If the vibration actuator 19 uses a giant magnetostrictive element, it is possible to generate sufficient vibrations that allow the branch pipe 10 to be probed. However, the buried pipe exploration device 1 according to the present embodiment explores the branch pipe 10 by simply comparing the vibrations of the respective measurement points captured by the four acceleration sensors 12A, B, C, and D provided in the sensor array 4. Therefore, even if the vibration becomes weak, it can be detected if any of the acceleration sensors 12A, B, C, D can catch the vibration.

  The magnitude of vibration is proportional to the reaction force of the vibration actuator 19. Therefore, the magnitude of vibration can be adjusted by adjusting the tightening force of the vertical tube clamping bolt 17. The magnitude of vibration can also be changed by the output of the excitation amplifier 3. Further, the signal generated by the excitation amplifier 3 may be a signal having any waveform as long as it can vibrate the branch pipe 10, and may be, for example, a rectangular wave or the like. Since the pipe vibrator 2 has a configuration in which the branch pipe 10 is sandwiched between the contact 18 and the fastening bolt 20, the size of the attachable branch pipe 10 is somewhat flexible.

  The vibration actuator 19 is not limited to one using a giant magnetostrictive material. That is, the vibration actuator 19 may be anything that can vibrate the branch pipe 10 at a specific frequency and with a sufficiently large amplitude. For example, an electrodynamic actuator composed of a coil and a permanent magnet. Alternatively, it may be an actuator composed of a piezo element.

  When fixing the pipe vibration exciter 2 to the branch pipe 10, first, the vertical pipe clamping bolts 17 are removed to separate the attachment jigs 16A and 16B. Further, the tightening bolt 20 is loosened. Then, the attachment jigs 16A and B are fastened with the vertical pipe clamping bolts 17 in a state where the branch pipe 10 is sandwiched between the attachment jigs 16A and B. Further, the tightening bolt 20 is tightened. Thereby, the pipe vibrator 2 is fixed to the branch pipe 10. When removing the pipe vibrator 2 from the branch pipe 10, the vertical pipe clamping bolt 17 is removed. Since the pipe shaker 2 is thus fixed so as to sandwich the exposed portion of the branch pipe 10, it is not necessary to open the inside of the branch pipe 10.

  FIG. 5 is a configuration diagram of the excitation amplifier 3. The excitation amplifier 3 includes an oscillator 21 and an amplifier 22 as shown in FIG. The oscillator 21 generates a sine wave having a specific frequency that is arbitrarily set. The amplifier 22 outputs a current obtained by amplifying the sine wave generated by the oscillator 21. The sine wave current output from the amplifier 22 is input to the vibration actuator 19. The specific frequency to be set is not particularly limited as long as the vibration transmitted to the branch pipe 10 is not easily attenuated in the ground, and is appropriately adjusted according to the material of the branch pipe 10 and the like.

FIG. 6 is a configuration diagram of the waveform monitor 5. As shown in FIG. 6, the waveform monitor 5 includes a filter 23 to which signals from the acceleration sensors 12A, B, C, and D are input, and an A / D that converts an analog signal output from the filter 23 into a digital signal. A CPU (Central Processing Unit) 25 for generating graphic images representing the signals from the respective acceleration sensors 12A, B, C, and D converted into digital signals by the converter 24 and the A / D converter 24 as waveforms; A memory 26 and a monitor 27 for displaying a graphic image generated by the cooperation of the CPU 25 and the memory 26 are provided. The CPU 25 executes the computer program stored in the memory 26 to store the amplitude data that is the measured values of the acceleration sensors 12A, B, C, and D output from the A / D converter 24. A graphic image of a waveform represented by a graph having the horizontal axis as the time axis and the vertical axis as the amplitude is generated. The filter 23 removes noise components included in the signals from the respective acceleration sensors 12A, B, C, and D, and a signal having an amplitude caused by vibration of components other than the vibration of the branch pipe 10 that is vibrated by the pipe shaker 2. Remove. That is, the filter 23 has a frequency higher than the frequency of the sine wave generated by the oscillator 21 of the excitation amplifier 3 among the analog signal waves having various frequencies included in the signals from the respective acceleration sensors 12A, B, C, and D. The signal wave having a frequency lower than the specific frequency is attenuated, so that the analog signal wave passing through the filter 23 is changed to a signal wave having substantially the same frequency as the frequency of the sine wave generated by the oscillator 21. It is a band pass filter to be As a result, the waveform of the non-specific frequency signal wave, which is a noise component, is not reflected in the waveform of the graphic image generated by the CPU 25 in cooperation with the memory 26, and the waveform of each measurement point can be easily compared.

  The waveform monitor 5 may be any monitor that can compare and display the vibration waveforms measured by the acceleration sensors 12A, B, C, and D. For example, an oscilloscope that displays each analog wave is used. May be arranged for each acceleration sensor 12A, B, C, D. In that case, since digital signal processing is unnecessary, the A / D converter 24, the CPU 25, the memory 26, and the like are unnecessary.

  FIG. 7 shows an example of a graphic image displayed on the monitor 27 when the buried pipe searching device 1 is used to search for the buried pipe. For example, when the sensor array 4 is temporarily installed at a point A shown in FIG. 3, a graphic image having a waveform as shown in FIG. The location where the sensor array 4 is installed is a location where the branch pipe 10 is likely to be embedded, and is determined by a user who is appropriately measured. Here, the measurer compares the amplitude of the waveform at each measurement point displayed on the monitor 27. In the case of a noise-like waveform as shown in FIG. 7A, it can be seen that although the amplitude of the waveform at measurement point 1 (acceleration sensor 12A) is slightly larger than the others, there is no particularly significant difference. In this case, the measurer determines that there is no branch pipe 10 under the sensor array 4 and considers exploring another location. When changing the position of the sensor array 4, it is preferable to move along the road 6. Note that which location is close to the branch pipe 10 can be grasped by considering the magnitude of the waveform amplitude at each measurement point. That is, at the point A, the amplitude of the waveform at the measurement point 1 was slightly larger than the others, so that it can be inferred that it is further to the side than the measurement point 1. Assume that the measurer repositions the sensor array 4 at, for example, the point B shown in FIG. 3 based on such a determination. In this case, a graphic image having a waveform as shown in FIG. As before, the measurer compares the amplitude of the waveform at each measurement point displayed on the monitor 27. In the case of the waveform as shown in FIG. 7B, it can be seen that the amplitude of the waveform at the measurement point 3 (acceleration sensor 12C) is clearly larger than the others. That is, the amplitude of the waveform at each measurement point is the largest at measurement point 3, and decreases in the order of measurement point 2, measurement point 4, and measurement point 1. The amplitudes of the waveforms observed at measurement point 2 and measurement point 4 are substantially the same. This is because the vibration that reaches each measurement point is attenuated according to the distance transmitted through the ground, and as shown in FIG. 8, the distance between the branch pipe 10 and each measurement point is different. As a result, the measurer can specify that the branch pipe 10 is almost directly below the measurement point 3. When there are two measurement points with the largest amplitude, it can be specified that the branch pipe 10 is in the vicinity of the middle between the two measurement points.

  If it is the said buried piping exploration apparatus 1, since the burying location of piping can be pinpointed by vibrating piping, it is not necessary to open the inside of piping. Therefore, it is not necessary to discharge the gas or liquid in the piping before the start of exploration. Moreover, it is not necessary to restore the flow of gas or liquid after the exploration is completed. Moreover, if it is the said buried piping exploration apparatus 1, since the burying location of piping can be pinpointed by vibrating a piping, vibration should just be transmitted and there is almost no restriction | limiting in the material of piping which can be searched.

  When adopting a configuration that analyzes the phase difference of reverberation in the order of hundreds to thousands of milliseconds and identifies the position of the buried pipe, the sound transmission speed varies depending on the material such as soil, concrete, and asphalt. It is extremely difficult to obtain a practical accuracy. However, since the above-described buried pipe exploration device 1 is an exploration method that simply compares the vibrations of a plurality of measurement points, it does not require a highly accurate measuring instrument or an advanced vibration analysis algorithm. Moreover, if it is the said underground piping exploration apparatus 1, although a highly accurate measurement apparatus and an advanced vibration analysis algorithm are not required, the precision required for construction can be obtained.

In the above embodiment, the sensor array 4 includes four acceleration sensors. However, the position and number of the acceleration sensors may be arbitrary. For example, 12 acceleration sensors may be provided as in a sensor array 4 ′ according to the modification shown in FIG. If the number of acceleration sensors is increased, the accuracy of exploration can be increased.

1 .... buried pipe exploration device, 2 .... pipe shaker, 3 .... excitation amplifier, 4 .... sensor array, 5 .... waveform monitor, 6 .... road, 7 .... main, 8 .... house , 9 · Site, 10 · · Branch pipe, 11 · · Gas meter, 12A, 12B, 12C, 12D · · Accelerometer, 13 · · Fixed stay, 14 · · Handle, 15 · · Signal cable, 16A, 16B · · Fixing jigs, 17 · · Vertical tube clamping bolts, 18 · · Contacts, 19 · · Vibrating actuators · 20 · · Tightening bolts · · · Oscillators · · · 22 · · Amplifiers · 23 · · Filters · 24 · · A / D converter, 25 · · CPU (Central Processing Unit), 26 · · Memory, 27 · · Monitor

Claims (5)

A buried pipe exploration method for identifying the position of a pipe buried underground,
With vibration applied to the exposed part of the pipe, the vibration of the ground is measured at a plurality of measurement points,
Compare the vibration of each measurement point to identify the position of the buried part of the pipe,
Underground pipe exploration method. The vibration applied to the exposed portion of the pipe is vibration of a specific frequency,
When specifying the position of the pipe, the position of the buried portion of the pipe is specified by comparing the vibration of the specific frequency among the vibrations of each measurement point.
The buried pipe exploration method according to claim 1. The buried pipe exploration method is to identify a pull-in position of a branch pipe that is branched from a main pipe buried in a road and drawn into a site adjacent to the road,
When measuring the vibration of the ground, the vibration of the ground between the exposed portion of the branch pipe and the road is measured at a plurality of measurement points arranged substantially along the road,
When specifying the position of the branch pipe, the vibration of each measurement point is compared to specify the drawing position of the branch pipe.
The buried piping exploration method according to claim 1 or 2. A buried pipe exploration device for identifying the position of a pipe buried in the ground,
Vibration means for applying vibration to the exposed portion of the pipe;
Vibration measuring means for measuring vibration of the ground at a plurality of measurement points in a state where the vibration means applies vibration to the pipe;
Display means for displaying the vibration of each measurement point measured by the vibration measuring means side by side so as to be comparable,
Underground piping exploration equipment. The vibration means is
A giant magnetostrictive actuator in contact with the exposed portion of the pipe;
A jig for fixing the giant magnetostrictive actuator to the pipe in a state where the giant magnetostrictive actuator is in contact with the exposed portion of the pipe,
The buried piping exploration device according to claim 4.

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