JP2020165862A - Measuring system of underground sound source position - Google Patents

Abstract

To provide a measuring system of an underground sound source position which can detect a sound generated at a sound source by using only a sensor which is arranged at an excavation rod without installing both a sensor and an artificial sound source, and can perform the detection without incurring a quotation cost and a measuring time by analyzing the detection.SOLUTION: In a measuring system of an underground sound source position, three pieces of sensors 7 arranged in prescribed positions of an excavation rod 3 sequentially detect individual sounds 15 which are generated by the abutment of a soil improvement agent injected from an injection part 4 of the excavation rod 3 on soil 2 as sound information including sound waves, and a data record means/analysis device 9 specifies the sound information which is detected by the sensors 7 by a frequency component, then data-records it, and specifies the individual sounds 15 by withdrawing a characteristic frequency component of a sound source by filtering the sound information. A position of the sound source is sequentially specified by a phase difference of the individual sounds 15 which are specified by the sensors 7, respectively, and a length in a vertical direction from the injection part up to the sensors 7.SELECTED DRAWING: Figure 1

Description

The present invention relates to a measurement system that identifies a position where an underground sound is generated by detecting an underground sound generated from a sound source in the ground with a sensor.

Conventionally, a measuring device and a measuring method of an underground sound source position for specifying a ground improvement position in the ground, a position of an excavation rod, and the like have been proposed.

As such a technique, a technique has been proposed in which an artificial sound source is installed at the tip of an excavation rod of an excavation construction machine, and the underground sound generated by the artificial sound source is detected by a plurality of sensors provided on the ground surface. (See, for example, Patent Documents 1 and 2).

In this technology, underground sound generated from an artificial sound source propagates in the ground, and when it reaches the ground surface, the sound waves are detected by multiple sensors, and the phase difference of the sound waves detected by the multiple sensors is calculated. The position of the excavation rod is specified by the calculation by the device.

JP 2012-58025 JP 2012-58038

However, in the method of measuring the underground sound source position described in Patent Documents 1 and 2, it is necessary not only to provide a plurality of sensors on the ground surface but also to provide an artificial sound source on the cutting rod of the excavation construction machine. , There was a problem that the cost of measurement was high.

Further, in the method for measuring the underground sound source position described in Patent Documents 1 and 2, since the sensor is provided on the ground surface, there is groundwater at a position higher than the position of the cutting rod, and the stratum is not a stratum. Depending on the conditions, it may be difficult for the sensor to detect the sound wave from the ground, and the measurement accuracy may not be maintained.

Therefore, it is an object of the present invention to provide an underground sound source position measuring system capable of accurately measuring the underground sound source position regardless of conditions and suppressing the cost of measurement.

In view of the above problems, in the invention according to claim 1, the liquid ejected substantially horizontally from the injection portion of the excavation rod provided at a position vertically dug down to a predetermined depth by boring is the ground or. At least two sensors arranged at predetermined positions of the excavation rod sequentially detect individual sounds generated by hitting an underground structure as sound information including sound sources, and the sound information detected by the sensors is used as data recording means. Is specified by the frequency component and data is recorded, the sound information detected by the sensor is filtered by the data recording means to extract a specific frequency component to identify the individual sound, and the analysis means is the analysis means of each of the sensors. The system is characterized in that the underground sound source position measurement system sequentially specifies the sound source position based on the phase difference of the identified individual sound and the length in the vertical direction between the respective sensors.

Further, in the invention according to claim 2, in addition to the configuration according to claim 1, measurement of the position of an underground sound source in which the liquid is a ground improvement agent for improving the ground or a reinforcing agent for reinforcing an underground structure. It is characterized by being a system.

Further, in the invention according to claim 3, in addition to the configuration according to claim 1 or 2, a through hole is provided in the wall material of the pipe of the excavation rod, and a steel plate is provided outside the through hole. The sensor is provided on the back surface of the steel plate, and a cushioning material is provided between the sensor and the steel plate and the wall material to provide a measurement system for the position of an underground sound source.

According to the invention of claim 1, at least two sensors are arranged on the excavation rod, and the sound information sequentially detected by the sensors is filtered by the data recording means to extract a specific frequency component to identify the individual sound. To do. Then, the analysis means detects that the specified individual sound has reached each sensor from the intensity of the specified solid sound of each sensor, and the time until the individual sound reaches each sensor and the sensor. In order to calculate the phase difference of each specified individual sound and specify the time until the individual sound reaches each sensor and the distance from the length in the vertical direction between the sensors measured in advance to the sound source position. With the distance, the depth of the known liquid injection position, and the injection direction, the underground sound source position can be sequentially specified three-dimensionally and accurately regardless of the conditions. Moreover, since it is not necessary to separately provide an artificial sound source, the cost of measurement can be suppressed.

Further, according to the invention of claim 2, in the injection system ground improvement step, the sound information of the sound source generated when the ground improvement agent hits the ground is sequentially detected by the sensor and transmitted to the data recording means, so that the data recording means Since the sound information is filtered and extracted into a specific frequency component, and the analysis means specifies the distance to the sound source position, the position of the sound source generated when the ground improving agent hits the ground can be specified sequentially and accurately in three dimensions. it can. As a result, the reachable range of the ground improving agent and the reinforcing agent can be measured with high accuracy.

In addition, in the reinforcement process of an aging underground structure, the sensor detects the sound information of the sound source generated when the reinforcing agent hits the underground structure and transmits it to the data recording means, and the data recording means filters the sound information. Since the analysis means specifies the distance to the sound source position by extracting the specific frequency component, the position of the sound source generated when the reinforcing agent hits the underground structure can be specified three-dimensionally and accurately.

Further, according to the invention of claim 3, the sensor is provided on the back surface of the steel plate of the through hole provided in the wall material of the pipe of the excavation rod, and the sensor and the cushioning material are provided between the steel plate and the wall material. , The cushioning material alleviates the vibration of the liquid flowing in the ground and the excavation rod, prevents the sensor from detecting noise, and can more accurately capture the collision sound generated when the liquid hits the ground or underground structure. The measurement accuracy can be further improved.

It is a schematic diagram of the measurement system of the underground sound source position in the injection system ground improvement construction method which concerns on Embodiment 1 of this invention. It is sectional drawing which shows the inside of the excavation rod of the underground sound source position measurement system which concerns on Embodiment 1. FIG. It is a figure which shows the polymerization waveform of the sound source detected by the sensor of the underground sound source position measurement system which concerns on Embodiment 1. FIG. It is a figure which Fourier-transformed the superposition waveform of the sound source detected by the sensor of the underground sound source position measurement system which concerns on Embodiment 1 and showed the waveform in the frequency domain. The waveforms of the frequency domain of the sound source in the frequency domain detected by the sensor of the underground sound source position measurement system according to the first embodiment are Fourier inverse transformed, and the figures shown in the time domain are shown in FIGS. This is an example of waveforms with different specific frequency components of a sound source. It is a schematic plan view which shows the injection state of the ground improvement agent from the injection part of the excavation rod of the underground sound source position measurement system which concerns on Embodiment 1. FIG. It is the schematic explaining the principle that the data recording / analysis apparatus which concerns on Embodiment 1 specifies the position of the ground improvement agent. It is a schematic diagram of the measurement system of the underground sound source position in the reinforcement process of the underground structure which concerns on Embodiment 2 of this invention.

Hereinafter, embodiments of the present invention will be described.
[Embodiment 1 of the invention]
1 to 7 show Embodiment 1 of the present invention.

As shown in FIGS. 1 and 6, the underground sound source position measuring system 100 according to the first embodiment excavates a ground improving agent as a liquid from the injection portion 4 at the tip of the excavation rod 3 of the construction machine 1. In the injection system ground improvement construction method in which the ground improvement is performed by injecting at high pressure while rotating 3, the position 5 of the sound source of the sound generated when the ground improvement agent hits the ground 2 is sequentially specified. In this embodiment, the underground sound source position measuring system 100 arranges the solid sound 15 generated when the ground improving agent sprayed at a high speed on the extension portion of the improvement range hits the ground 2 on the excavation rod 3. The position 5 of the sound source is specified by detecting and analyzing with the three sensors 7, and thereby the improvement range of the ground 2 is specified.

Further, in the first embodiment, as shown in FIG. 1, the ground improving agent is injected into the ground 2 at one place, and the sound information captured by the sensor 7 is generated when the ground improving agent hits the ground 2. Contains the sound of

Further, in the first embodiment, the sound information is detected while the ground improving agent is injected into the ground 2, and the ground improving agent is injected as shown by the arrow A in FIG. The position 5 of the sound source in the ground is sequentially measured in a state where the direction changes (rotates) in the ground 2.

As shown in FIG. 1, the underground sound source position measurement system 100 of the first embodiment detects sound waves including the individual sound 15 generated at the sound source position 5 as sound information, and wires the signal of the sound information. The sensor 7 transmitted by 13, the amplifier 8 that amplifies the signal of the sensor 7, and the data recording / analysis device 9 that receives the signal amplified by the amplifier 8 and records the data and analyzes it to identify the position 5 of the sound source. It has. In this embodiment, the data recording / analysis device 9 is a device having both a data recording means and an analysis means.

The sensor 7 detects a sound having a wide range of frequency components from 20 Hz to 20000 Hz, which can measure the individual sound 15, and in this embodiment, a sound field sound pressure type microphone is provided. The sensor 7 may be not only a sound field sound pressure type microphone, but also a sound field sound pressure type geophone or an accelerometer.

Further, as shown in FIG. 2, one sensor 7 is provided on the back surface of the steel plate 10 provided on the outside of each of the three through holes 12 provided in the wall material of the excavation rod 3 at predetermined intervals. Three are provided, and a cushioning material 11 is provided between the sensor 7 and the steel plate 10 and the wall material of the excavation rod 3, and the sensor 7, the steel plate 10 and the cushioning material 11 are the same as the wall surface of the wall material of the excavation rod 3. It is provided so as to be a surface. The cushioning material 11 also serves as a waterproof material.

Further, the sensors 7 are mounted on a surface in the same direction as the direction of the injection unit 4 for injecting the ground improving agent, and all the sensors 7 are provided on the wall surface in the same direction along the vertical direction. Then, as the excavation rod 3 rotates, the injection unit 4 rotates, and at the same time, each sensor 7 also rotates so as to face the same direction as the injection unit 4.

Further, these sensors 7 detect the individual sound 15 generated at the position 5 of the sound source, and the individual sound 15 of the sound source shown in FIG. 5 and the noise generated in other construction work are superimposed, as shown in FIG. The sound wave of the waveform is configured to be transmitted to the data recording / analysis device 9 via the amplifier 8 as sound information (signalized here).

On the other hand, as shown in FIG. 1, the amplifier 8 is connected to each of the three sensors 7 by a wired 13 provided in the inner tube of the excavation rod 3, and the individual sound detected and transmitted by each sensor 7. It is configured to amplify the sound wave signal including 15 and transmit it to the data recording / analysis device 9.

On the other hand, the data recording / analysis device 9 receives the signal of the sound wave including the solid sound 15 amplified by the amplifier 8, performs A / D conversion, separates each frequency component, and performs the solid sound 15 in real time. It is equipped with a computer that analyzes the specific frequency component, phase, and amplitude intensity of the sound wave to identify the position 5 of the sound wave.

As shown in FIG. 3, the data recording / analysis device 9 receives signals received from the three sensors 7 by this computer in a time domain in which the horizontal axis is the detection time and the vertical axis is the components such as voltage and current. , The waveform of the sound source is configured to be detected by the superimposed waveform.

Further, this computer is configured to Fourier transform the waveform in the time domain of the sound source and calculate the waveform in the frequency domain with the horizontal axis as the frequency component and the vertical axis as the amplitude or phase, as shown in FIG. ing.

Further, the computer records a plurality of characteristic specific frequencies of the individual sound 15 generated when the ground improving agent hits the ground 2. The computer identifies the specific frequency component 15 of the sound source by comparing the recorded characteristic specific frequency with the frequency having an amplitude in the waveform in the frequency domain of the sound source as shown in FIG. The computer is configured to separate and extract the waveforms of only the characteristic frequency components of the sound source by filtering the waveforms of other frequency components from the waveforms of the specific frequency region of the specified sound source. There is.

Further, the computer inversely Fourier transforms the waveform of the frequency domain of the characteristic frequency component of the separated and extracted sound source, and the time as shown in FIGS. 5A, 5B, and 5C, respectively. It is configured to calculate the waveform of the region.

Furthermore, this computer filters, separates, and extracts the characteristic frequency components of the sound source from each of the waveforms of the sound waves of the individual sound 15 of the sound source detected by each of the three sensors 7, and extracts the characteristic frequency components of the sound source. It is configured to detect three waveforms of each sound source as shown in FIGS. 5A, 5B, and 5C.

Further, the computer analyzes the phase difference of the time component in the horizontal axis direction of the waveform of the specific frequency component of each of the three sound sources obtained by analyzing the signals from each of the sensors 7, and the individual sound 15 Is configured to calculate the time until each sensor 7 arrives and specify the position 5 of the sound source. The principle and analysis procedure for the data recording / analysis device 9 to specify the position 5 of the sound source by the computer will be described in detail in the measurement method.

In addition, the data recording / analysis device 9 records data on the frequency of the individual sound 15 generated on the contact surface between a plurality of types of ground improving agents having different components and the ground 2, and the intensity of the amplitude of the frequency component. , The computer is configured to compare and analyze the frequency characteristics and amplitude intensity of a specific frequency component of the individual sound 15 to identify the hardness and material components of the ground 2 in contact with the sound.

Further, the data recording / analysis device 9 analyzes the signal of the individual sound 15 generated on the contact surface when the ground improving agent, which is injected by the computer and constantly moves in the ground 2, collides with the ground 2, and positions the sound source. It is configured to identify 5.

Next, a measurement method by the underground sound source position measurement system 100 according to this embodiment will be described.

First, the operator provides the sensors 7a, 7b, 7c on the back surface of the steel plate 10 provided outside the through hole 12 at a predetermined position of the excavation rod 3, and the sensors 7a, 7b, 7c, the steel plate 10, and the excavation rod 3 A cushioning material 11 is provided between the wall materials of the above, so that the sensors 7a, 7b, 7c, the steel plate 10, and the cushioning material 11 are flush with the wall surface of the wall material of the excavation rod 3. At this time, the sensors 7a, 7b, 7c are attached to the surface in the same direction as the direction of the injection unit 4 for injecting the ground improving agent, and the sensors 7a, 7b, 7c are all perpendicular to the wall surface in the same direction of the excavation rod 3. Provide along the direction.

Further, as shown in FIG. 7, the vertical length H ₁ from the injection unit 4 to the sensor 7a, the vertical length H ₂ from the injection unit 4 to the sensor 7b, and the vertical length from the injection unit 4 to the sensor 7c. Measure the length H _{3 in the} direction. In addition, the distance from the injection unit 4 to the ground surface where the excavation rod 3 is excavated is measured.

Next, the operator causes the excavation rod 3 to excavate vertically from the ground surface to the ground 2. At this time, the operator confirms the direction in which the injection unit 4 injects the ground improving agent. Then, the operator activates the sensor 7, the amplifier 8, and the data recording / analysis device 9 of the underground sound source position measurement system 100, and as shown in FIGS. 1 and 6, the operator injects the excavation rod 3 of the construction machine 1. The ground improving agent is sprayed from the part 4.

Then, the ground improving agent hits the ground 2, and a sound wave including the solid sound 15 is generated from the position 5 of the sound source, which is the contact surface thereof. This sound wave propagates through the solid sound propagation path 6 in the ground 2 and reaches the sensors 7a, 7b, 7c. The sensors 7a, 7b, 7c detect the sound information of the sound source including the individual sound 15 of the reached sound source, and the respective sensors 7a, 7b, 7c transmit the sound information signal including the individual sound 15 to the wired 13 and the amplifier 8. Is received by the data recording / analysis device 9 via.

The data recording / analysis device 9 uses the sound source information signal received from the sensor 7 as a sound source sound source in a time domain with the horizontal axis as the detection time and the vertical axis as the components such as voltage and current, as shown in FIG. The waveform of is detected by the overlapping waveform.

Further, the data recording / analysis device 9 Fourier transforms the signal of the waveform in the time domain of this sound source by a computer, and has a frequency whose horizontal axis is the frequency component and whose vertical axis is the amplitude or phase, as shown in FIG. Calculate on the waveform of the region.

At this time, the data recording / analysis device 9 is generated by a computer at a frequency having an amplitude in the waveform of the sound source in this frequency region and a contact surface between the ground improving agent and the ground recorded in advance, as shown in FIG. The specific frequencies of the individual sounds 15 are compared. Then, the individual sound 15 generated at the contact surface between the ground improvement agent and the ground 2 recorded in advance for a frequency having an amplitude in the waveform of the sound source in a specific frequency region as shown in FIG. Filtering is performed so as to extract the characteristic specific frequency of, and the waveforms of the ones that almost match are separated and extracted.

Further, the data recording / analysis apparatus 9 Fourier inverse transforms the waveforms in the frequency domain of the characteristic frequency components of the separated and extracted individual sounds 15 by a computer, respectively, and (a) and (b) of FIG. ), The waveform of the sound source as shown in (c) is extracted. Since the waveforms of these sound sources are detected by the three sensors 7a, 7b, and 7c, they are extracted three by three. Further, in the waveforms of these three extracted sound sources, since the distance between the position 5 of the sound source and each sensor 7 is different, the phase of the time component on the horizontal axis is different due to the difference in propagation time.

Here, FIG. 7 shows the principle that the computer of the data recording / analysis device 9 analyzes the phase difference of the time component in the horizontal axis direction of the waveform of the sound source of each sensor 7 to specify the position of the ground improving agent. Will be described using.

First, as shown in FIG. 7, let L be a substantially horizontal distance from the position 5 of the specified sound source to the injection unit 4. Further, the distance from the sound source position 5 to the sensor 7a is L ₁ , the distance from the sound source position 5 to the sensor 7b is L ₂ , and the distance from the sound source position 5 to the sensor 7c is L ₃ . Further, the time until the sensor 7a detects the individual sound 15 is t ₁ , the time until the sensor 7b detects the individual sound 15 is t ₂ , and the time until the sensor 7c detects the individual sound 15 is t _3. , The difference in time until the sensor 7b and the sensor 7a detect the individual sound 15 (t _2- t ₁ ) is S ₁ , and the time until the sensor 7c and the sensor 7a detect the individual sound 15 (t _3- t _1). ) Is S ₂ .

At this time, since the velocity of the individual sound 15 is the speed of sound c, the length of S ₁ × c corresponds to (L _2- L ₁ ), and the length of S ₂ × c becomes (L ₃ −L ₁ ). Equivalent to.

Therefore, the ratio of S ₁ and S ₂ is as shown in the following equation (1).

また、Ｌ_１，Ｌ_２，Ｌ_３は、ピタゴラスの定理により、それぞれ以下の式（２）〜（４）の通りになる。

Further, L ₁ , L ₂ , and L ₃ are as shown in the following equations (2) to (4) according to the Pythagorean theorem.

従って、式（１）に式（２）、式（３）、式（４）を代入することにより、以下の式（５）の通りになる。

Therefore, by substituting the equations (2), (3), and (4) into the equation (1), the following equation (5) is obtained.

データ収録・解析装置９は、式（５）により、音源の位置５から噴射部４までの水平距離Ｌを算出し、算出した音源の位置５から噴射部４までの水平距離Ｌと予め計測した噴射部４から掘削ロッド３の地表面までの距離から音源の位置５を三次元的に特定する。

The data recording / analysis device 9 calculated the horizontal distance L from the sound source position 5 to the injection unit 4 by the equation (5), and measured the calculated horizontal distance L from the sound source position 5 to the injection unit 4 in advance. The position 5 of the sound source is three-dimensionally specified from the distance from the injection unit 4 to the ground surface of the excavation rod 3.

The operator confirms the position 5 of the sound source specified by the data recording / analysis device 9 and proceeds with the work process.

As described above, according to the underground sound source position measurement system 100 of the first embodiment, the three sensors 7 are arranged on the excavation rod 3, and the sound information sequentially detected by the sensors 7 is recorded by the data recording means. The individual sound 15 is specified by filtering to extract a specific frequency component. Then, the analysis means calculates the phase difference of the specified individual sound 15 of each of the sensors 7, calculates each time until the individual sound 15 reaches each sensor 7, and the calculated individual sound 15 is calculated. Since the position 5 of the sound source is specified from the time when it reaches each sensor 7, the length in the vertical direction from the injection unit 4 to each sensor 7 measured in advance, the depth of the injection unit 4, and the injection direction, the ground is not affected by the conditions. The position of the middle sound source can be specified three-dimensionally and accurately, and in the ground improvement process, the position of the sound source generated when the ground improvement agent hits the ground is sequentially specified three-dimensionally and accurately, so that the improvement range of the ground 2 Can be specified accurately. Moreover, since it is not necessary to separately provide an artificial sound source, the cost of measurement can be suppressed.

Further, in the underground sound source position measurement system 100, the data recording / analysis device 9 filters the sound information detected by the sensor 7, and the characteristic of the sound source generated at the contact surface between the ground improving agent and the ground 2. Specific frequency components are separated and detected. Therefore, the characteristic frequency of the sound source can be selected and detected without being disturbed by the noise in the ground 2, and the position 5 of the sound source can be accurately specified.

Further, in the underground sound source position measurement system 100, the data recording / analysis device 9 filters the sound information sequentially detected by the sensor 7, and the characteristic specific frequency component of the individual sound 15 generated by the sound source. Is separated and detected individually, so the position of the sound source can be specified with high accuracy.

Further, in the underground sound source position measurement system 100, the data recording / analysis device 9 A / D-converts the sound information detected by the plurality of sensors 7 and performs frequency analysis and phase analysis of the sound source by a computer. In order to identify the position 5 of the sound source in the ground 2 in real time, the operator can confirm the position 5 of the sound source during the injection type ground fine process, and the progress of the process (ground improvement range) can be confirmed. It is possible to take measures such as confirmation and review of process settings (improved diameter and specifications).

Furthermore, in this underground sound source position measurement system 100, the data recording / analysis device 9 has different components from the characteristic frequency component 15 of the sound source and the ground improving agent of a plurality of types of components recorded in advance. Workers to compare and analyze data on the frequency of individual sounds 15 generated on the contact surface between multiple types of ground improvement agents and the ground 2 to identify the hardness and material components of the ground 2 with which the ground improvement agents come into contact. Can change the work process (improved diameter and specifications) from the hardness and material components of the ground 2 under construction.

Further, in the underground sound source position measurement system 100, the data recording / analysis device 9 is injected during the injection type ground improvement process and travels horizontally through the ground 2 to hit the ground 2. In order to analyze the sound 15 in real time and sequentially identify the boundary position between the ground improving agent and the ground 2, the operator sequentially confirms the position 5 of the moving sound source and deals with the individual sound 15 of the moving sound source. can do.

Further, in the underground sound source position measurement system 100, the sensor 7 is provided on the back surface of the steel plate 10 of the through hole 12 provided in the wall material of the pipe of the excavation rod 3, and is provided between the sensor 7 and the steel plate 10 and the wall material. By providing the cushioning material 11 so that the sensor 7, the steel plate 10, and the cushioning material 11 are flush with the wall surface of the wall material of the excavation rod 3, the cushioning material 11 is provided in the ground 2 and the excavation rod 3. The vibration of the flowing ground improvement agent can be alleviated, the sensor can prevent the sensor from detecting noise, and the collision sound generated when the ground improvement agent hits the ground can be captured more accurately, and the measurement accuracy can be further improved.

Further, since the cushioning material 11 also serves as a waterproof material, even if the ground improving agent flowing in the excavation rod 3 comes into contact with the sensor 7, it can be prevented from breaking down.
[Embodiment 2 of the Invention]
Next, the second embodiment of the present invention will be described.

In the description of the second embodiment, only the part different from the first embodiment will be described, and the part overlapping with the first embodiment will be omitted.

FIG. 8 shows a second embodiment of the present invention.

As shown in FIG. 8, the underground sound source position measuring system 100 according to the second embodiment has an aged underground structure 16 in the ground 2 from the injection portion 4 at the tip of the excavation rod 3 of the construction machine 1. In the injection system structure reinforcement method for reinforcing the underground structure 16 by injecting a reinforcing agent as a liquid to reinforce the ground structure 16, the position 5 of the sound source of the sound generated when the reinforcing agent hits the underground structure 16. Is to identify.

In the second embodiment, the underground sound source position measuring system 100 makes an individual sound generated by the reinforcing agent injected at a high speed on the extension portion of the improved range hitting the underground structure 16 with the excavation rod 3. The position 5 of the sound source is specified by detecting and analyzing the three sensors 7 arranged in the above.

The data recording / analysis device 9 of the second embodiment records a plurality of data on the frequency of the individual sound generated when the reinforcing agent hits the underground structure 16 and the amplitude intensity of the frequency component, and is detected by the sensor 7. It is configured to identify whether the reinforcing agent has reached the underground structure 16 by comparing the frequency of the individual sound in which the frequency of the sound information of the sound is recorded and the amplitude intensity of the frequency component.

Other configurations of the underground sound source position measurement system 100 according to the second embodiment are the same as those of the first embodiment.

Next, a measurement method by the underground sound source position measurement system 100 according to the second embodiment will be described.

First, as in the first embodiment, the operator provides the sensors 7a, 7b, 7c on the back surface of the steel plate 10 provided outside the through hole 12 at a predetermined position of the excavation rod 3, and the sensors 7a, 7b, 7b, A cushioning material 11 is provided between the 7c and the steel plate 10 and the wall material of the excavation rod 3 so that the sensors 7a, 7b, 7c, the steel plate 10 and the cushioning material 11 are flush with the wall surface of the wall material of the excavation rod 3. Provide. At this time, the sensors 7a, 7b, 7c are attached to the surface in the same direction as the direction of the injection unit 4 for injecting the reinforcing agent, and the sensors 7a, 7b, 7c are all perpendicular to the wall surface in the same direction of the excavation rod 3. Provided along.

At this time, as in the first embodiment, as shown in FIG. 7, the vertical length H ₁ from the injection unit 4 to the sensor 7a and the vertical length H ₂ from the injection unit 4 to the sensor 7b. measuring the vertical length H ₃ from the injection unit 4 to the sensor 7c. In addition, the distance from the injection unit 4 to the ground surface where the excavation rod 3 is excavated is measured.

Next, the operator causes the excavation rod 3 to excavate vertically from the ground surface to the ground 2. At this time, the operator confirms the direction in which the injection unit 4 injects the reinforcing agent. Then, the operator activates the sensor 7, the amplifier 8, and the data recording / analysis device 9 of the underground sound source position measurement system 100, and as shown in FIG. 8, from the injection unit 4 of the excavation rod 3 of the construction machine 1. , Inject the reinforcing agent.

Then, the reinforcing agent hits the underground structure 16 and generates sound waves including solid sounds from the position 5 of the sound source which is the contact surface thereof. This sound wave propagates through the solid sound propagation path 6 in the ground 2 and reaches the sensors 7a, 7b, 7c. The sound information of the reached sound waves is transmitted by the sensors 7a, 7b, and 7c, and is received by the data recording / analysis device 9 via the amplifier 8.

The data recording / analysis device 9 detects the signal of the sound wave information received from the sensor 7 as a waveform in which the waveforms of the sound waves in the time domain with the horizontal axis as the detection time and the vertical axis as the components such as voltage and current are duplicated. ..

Further, the data recording / analysis device 9 Fourier transforms the signal of the waveform of the time domain of the sound wave by a computer, and calculates the waveform in the frequency domain with the horizontal axis as the frequency component and the vertical axis as the amplitude or phase.

At this time, the data recording / analysis device 9 uses a computer to generate individual sounds generated at the contact surface between the frequency having an amplitude in the waveform of the sound source in this frequency region and the pre-recorded reinforcing agent and the underground structure 16. Compare specific frequencies. Then, by a computer, for a frequency having an amplitude in the waveform of the sound source in a specific frequency region, a characteristic specific specific individual sound generated at the contact surface between the pre-recorded reinforcing agent and the underground structure 16 is specified. Filter to extract the frequency, and separate and extract the waveforms that almost match.

Further, the data recording / analysis device 9 Fourier inverse transforms the waveforms in the frequency domain of the characteristic frequency components of the separated and extracted individual sounds by a computer, and the horizontal axis is the time component and the vertical axis is the amplitude. Alternatively, the waveform of the time component used as the phase is calculated.

Since the waveforms of the sound sources of this time component are detected by the three sensors 7a, 7b, and 7c, they are extracted three by three. Further, in the waveforms of these three extracted sound sources, since the distance between the position 5 of the sound source and each sensor 7 is different, the phase of the time component on the horizontal axis is different due to the difference in propagation time.

The computer of the data recording / analysis device 9 analyzes the phase difference of the time component of the sound wave waveform of each sensor 7, and the reinforcing agent reaches the underground structure 16 and hits the position 5 of the sound source generated. The principle of specifying the above is the same as that of the first embodiment.

The operator confirms the position 5 of the sound source specified by the data recording / analysis device 9 and proceeds with the work process.

As described above, according to the underground sound source position measuring system 100 of the second embodiment, the three sensors 7 are arranged on the excavation rod 3, and the sound information sequentially detected by the sensors 7 is recorded by the data recording means. Filtering is performed to extract specific frequency components to identify individual sounds. Then, the analysis means calculates the phase difference of the specified individual sound of each of the sensors 7, calculates each time until the individual sound reaches each sensor 7, and the calculated individual sound is the respective sensor. Since the sound source position 5 is specified from the time when the sound reaches 7 and the length in the vertical direction from the injection unit 4 to each sensor 7 measured in advance, the depth of the injection unit 4, and the injection direction, the underground sound source position regardless of the conditions. Can be specified three-dimensionally and accurately, and in the reinforcement process of the aged underground structure 16, the position of the sound source generated when the reinforcing agent hits the underground structure 16 is sequentially specified three-dimensionally and accurately. be able to. Moreover, since it is not necessary to separately provide an artificial sound source, the cost of measurement can be suppressed.

Further, in the underground sound source position measurement system 100, the sensor 7 is provided on the back surface of the steel plate 10 of the through hole 12 provided in the wall material of the pipe of the excavation rod 3, and is provided between the sensor 7 and the steel plate 10 and the wall material. By providing the cushioning material 11 so that the sensor 7, the steel plate 10, and the cushioning material 11 are flush with the wall surface of the wall material of the excavation rod 3, the cushioning material 11 is provided in the ground 2 and the excavation rod 3. The vibration of the flowing reinforcing agent can be alleviated, the sensor can prevent the sensor from detecting noise, and the collision sound generated when the reinforcing agent hits the underground structure 16 can be captured more accurately, and the measurement accuracy can be further improved. ..

Needless to say, the first and second embodiments are examples of the present invention, and does not mean that the present invention is limited to the first and second embodiments.

For example, in the first and second embodiments, three sensors 7 are arranged on the excavation rod 3, but as long as there are two or more sensors 7, any number of sensors 7 may be arranged.

Further, in the first and second embodiments, the sensor 7 is arranged at a position above the injection portion 4 of the excavation rod 3, but the excavation rod 3 extends below the injection portion 4, and the sensor 7 is provided there. It may be arranged.

Further, in the first and second embodiments, the sensor 7 and the amplifier 8 are connected by a wired 13 passing through the inner tube of the excavation rod 3, but the sensor 7 provided on the excavation rod 3 and existing in the ground 2 is used. It suffices that the detected individual sound 15 is transmitted so that it can be received by the amplifier 8 and the data recording / analysis device 9 provided on the ground. For example, the wavelength of the signal of the individual sound 15 detected by the sensor 7. May be configured to be a long wave and transmitted to the amplifier 8 wirelessly.

Further, in the first and second embodiments, one amplifier 8 is provided between the three sensors 7 and the data recording / analysis device 9, but the signal of the individual sound 15 transmitted by the sensor 7 is the data recording / analysis. The size may be large enough to be received and analyzed by the device 9, and the amplifier 8 may not be provided, or one amplifier 8 may be connected to each of the sensors 7.

Furthermore, in the first and second embodiments, the data recording / analysis device 9 may be provided with a monitor that displays the position of the specified sound source in the ground.

Further, in the first embodiment, the position of the sound source generated when the ground improving agent hits the ground in the injection type ground improving process is specified, and in the second embodiment, the reinforcing agent in the reinforcing process of the aged underground structure is the underground structure. The underground sound source position measurement system 100 is used to identify the position of the sound source generated by hitting an object, but if the sound source is in the ground, water is flowing using this underground sound source position measurement system 100. It is also possible to specify the position of another sound source, such as the position or the position where another machine is operating.

Furthermore, in the above-described first and second embodiments, the data recording / analysis device that also serves as both the data recording means and the analysis means is provided, but the present invention is not limited to this, and the data recording means and the analysis means are used. May be configured with different devices.

1 …… Construction machine 2 …… Ground 3 …… Excavation rod 4 …… Injection part 5 …… Sound source position 6 …… Individual sound propagation path 7 (7a, 7b, 7c) …… Sensor 8 …… Amplifier 9 …… Data recording / analysis device (data recording means, analysis means)
10 …… Steel plate 11 …… Cushioning material 12 …… Through hole 13 …… Wired 15 …… Solid sound 16 …… Underground structure 100 …… Underground sound source position measurement system H ₁ …… From injection section to sensor 7a Vertical length H ₂ …… Vertical length from the injection part to the sensor 7b H ₃ …… Vertical length from the injection part to the sensor 7c L …… Solid sound generation position from the injection part (sound source) ) Approximately horizontal distance

Claims (3)

The solid sound generated when the liquid ejected in the substantially horizontal direction from the injection part of the excavation rod provided at a position dug vertically to a predetermined depth by boring hits the ground or the underground structure is the predetermined sound of the excavation rod. At least two sensors located at the position sequentially detect as sound information including sound waves,
The data recording means identifies the sound information detected by the sensor by the frequency component and records the data.
The sound information detected by the sensor is filtered by the data recording means to extract a specific frequency component, and the individual sound is specified.
An underground sound source position measuring system, wherein the analysis means sequentially identifies the sound source position based on the phase difference of the individual sound specified by each of the sensors and the vertical length between the sensors. .. The underground sound source position measuring system according to claim 1, wherein the liquid is a ground improving agent for improving the ground or a reinforcing agent for reinforcing an underground structure. A through hole is provided in the wall material of the pipe of the excavation rod, a steel plate is provided outside the through hole, the sensor is provided on the back surface of the steel plate, and cushioning is provided between the sensor and the steel plate and the wall material. The underground sound source position measuring system according to claim 1 or 2, wherein the material is provided.

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