JP7271812B2 - Underground sound source position measurement system - Google Patents

Description

TECHNICAL FIELD The present invention relates to a measurement system that identifies the location of underground sound by detecting the underground sound generated from a sound source in the ground with a sensor.

Conventionally, there have been proposed underground sound source position measuring devices and measuring methods for specifying ground improvement positions in the ground, positions of excavation rods, and the like.

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

With this technology, underground sound generated by an artificial sound source propagates through the ground, and when it reaches the ground surface, the sound waves are detected by multiple sensors, and the phase difference between the sound waves detected by the multiple sensors is calculated. The device computes to identify the position of the drilling rod.

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 machine. , there is a problem that the price cost of the measurement increases.

In addition, in the methods 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 stratified. Depending on the conditions, it may be difficult for the sensor to detect sound waves from the ground, making it impossible to maintain measurement accuracy.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an underground sound source position measuring system capable of accurately measuring the position of an underground sound source regardless of conditions and reducing the cost of measurement.

In view of the above-mentioned problems, the invention according to claim 1 provides liquid ejected in a substantially horizontal direction from an ejection part of an excavation rod provided at a position vertically dug down to a predetermined depth by boring. At least two sensors arranged at predetermined positions on the excavation rod successively detect individual sounds generated by hitting underground structures as sound information including sound waves, and the sound information detected by the sensors is recorded as data recording means. identifies and records data according to frequency components, filters the sound information detected by the sensor by the data recording means, extracts a specific frequency component, identifies the individual sound, and the analysis means identifies the individual sound of each of the sensors. The underground sound source position measuring system is characterized in that the sound source position is sequentially specified based on the specified phase difference of the individual sound and the vertical length between the respective sensors.

In addition, the invention according to claim 2, in addition to the configuration according to claim 1, the liquid is a soil improvement agent for soil improvement or a reinforcing agent for reinforcing underground structures. It is characterized by being made into a system.

Furthermore, the invention according to claim 3, in addition to the configuration according to claim 1 or 2, is provided with a through hole in the wall material of the pipe of the drilling rod, a steel plate is provided outside the through hole, and the The system is characterized in that the sensor is provided on the back surface of a steel plate, and a cushioning material is provided between the sensor, the steel plate, and the wall material.

According to the first aspect of the invention, at least two sensors are arranged on the drilling rod, sound information sequentially detected by the sensors is filtered by the data recording means, and specific frequency components are extracted to specify the individual sound. do. Then, the analysis means detects that the specified individual sound reaches each sensor from the intensity of the specified individual sound of each sensor, and the time until the individual sound reaches each sensor and the sensor To calculate the phase difference of each of the specified individual sounds and to specify the distance to the sound source position from the time it takes for the individual sound to reach each sensor and the vertical length between the sensors that has been measured in advance. , the position of the underground sound source can be sequentially specified three-dimensionally with high accuracy regardless of the conditions by using the distance, the known depth of the injection position of the liquid, and the injection direction. Moreover, since there is no need to separately provide an artificial sound source, the cost of measurement can be reduced.

Further, according to the invention of claim 2, in the injection system ground improvement process, the sensor sequentially detects the sound information of the sound source generated by the soil improvement agent hitting the ground and transmits it to the data recording means, and the data recording means Sound information is filtered to extract specific frequency components, and the analysis means specifies the distance to the sound source position. Therefore, the position of the sound source generated by the soil improvement agent hitting the ground can be specified three-dimensionally and accurately. can. As a result, it is possible to accurately measure the reaching range of the soil improvement agent and the reinforcing agent.

In addition, in the reinforcement process of aged underground structures, a sensor detects the sound information of the sound source generated by the reinforcing material hitting the underground structure and transmits it to the data recording means, and the data recording means filters the sound information. Since the analysis means identifies the distance to the sound source position by extracting the specific frequency component by using the sine wave, the position of the sound source generated by the reinforcing material hitting the underground structure can be identified three-dimensionally with high accuracy.

Furthermore, according to the third aspect of the invention, 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 drilling rod, and a buffer material is provided between the sensor and the steel plate and the wall material. , the cushioning material reduces the vibration of the liquid flowing in the ground and the drilling rod, prevents the sensor from detecting noise, and can more accurately capture the collision sound generated by the liquid hitting the ground or underground structures, Measurement accuracy can be further improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a measurement system for an underground sound source position in an injection-based ground improvement method according to Embodiment 1 of the present invention; 4 is a cross-sectional view showing the inside of the excavation rod of the underground sound source position measuring system according to the first embodiment; FIG. 4 is a diagram showing superimposed waveforms of sound sources detected by a sensor of the underground sound source position measuring system according to the first embodiment; FIG. FIG. 4 is a diagram showing a waveform in the frequency domain obtained by Fourier transforming a superimposed waveform of sound sources detected by the sensor of the underground sound source position measurement system according to the first embodiment; In the diagrams showing in the time domain the inverse Fourier transform of the frequency domain waveform of the frequency domain sound source detected by the sensor of the underground sound source position measurement system according to the first embodiment, (a) to (c) are It is an example of different waveforms of specific frequency components of a sound source. FIG. 4 is a schematic plan view showing a state of injection of a soil improvement agent from an injection portion of an excavation rod of the underground sound source position measurement system according to the first embodiment; It is a schematic diagram for explaining the principle that the data recording / analysis device according to the first embodiment specifies the position of the soil improvement agent. FIG. 10 is a schematic diagram of an underground sound source position measurement system in the underground structure reinforcement process according to Embodiment 2 of the present invention;

Embodiments of the present invention will be described below.
[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 measurement system 100 according to the first embodiment is configured such that a soil improvement agent as a liquid is injected from the injection part 4 at the tip of the excavation rod 3 of the construction machine 1 into the excavation rod. In the injection system ground improvement method in which 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 soil improvement agent hits the ground 2 is sequentially specified. In this embodiment, the underground sound source position measurement system 100 arranges the individual sound 15 generated by the soil improvement agent sprayed at high speed on the extension of the improvement range and hitting the ground 2 on the excavation rod 3. The position 5 of the sound source is specified by detecting and analyzing the three sensors 7, thereby specifying the improvement range of the ground 2. FIG.

In addition, in this Embodiment 1, as shown in FIG. contains a sound.

Furthermore, in this Embodiment 1, the sound information is detected while the soil improvement agent is being sprayed into the ground 2, and the soil improvement agent is sprayed as shown by arrow A in FIG. The position 5 of the sound source in the ground is successively measured while the direction changes (rotates) in the ground 2 .

As shown in FIG. 1, the underground sound source position measurement system 100 of Embodiment 1 detects, as sound information, sound waves including individual sounds 15 generated at a sound source position 5, and transmits a signal of the sound information to a wire. 13, an amplifier 8 that amplifies the signal of the sensor 7, and a data recording/analyzing device 9 that receives the signal amplified by the amplifier 8, records the data, analyzes it, and specifies the position 5 of the sound source. It has In this embodiment, the data recording/analyzing device 9 serves as both data recording means and analyzing means.

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

Further, as shown in FIG. 2, the sensors 7 are arranged one by one on the back surface of the steel plate 10 provided outside each of the three through-holes 12 provided in the wall material of the drilling rod 3 at predetermined intervals. A buffer material 11 is provided between the sensor 7 and the steel plate 10 and the wall material of the drilling rod 3. It is provided so that it becomes a plane. The cushioning material 11 also serves as a waterproof material.

Furthermore, the sensor 7 is attached to the surface in the same direction as the direction of the injection part 4 that injects the soil improvement agent, and all the sensors 7 are provided on the wall surface in the same direction along the vertical direction. 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. Waveform sound waves are configured to be transmitted to the data recording/analyzing device 9 via the amplifier 8 as sound information (in this case, signalized).

On the other hand, the amplifier 8, as shown in FIG. 15 is amplified and transmitted to the data recording/analyzing device 9 .

On the other hand, the data recording/analyzing device 9 receives a sound wave signal including the individual sound 15 amplified by the amplifier 8, A/D converts it, separates it by frequency component, and converts the individual sound 15 in real time. is equipped with a computer that analyzes specific frequency components, phases, and amplitude intensities possessed by , and specifies the position 5 of the sound source.

The data recording/analyzing device 9 uses this computer to record the signals received from the three sensors 7 in the time domain, as shown in FIG. , is configured to detect a waveform in which the waveforms of the sound source are superimposed.

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

Furthermore, this computer records a plurality of characteristic specific frequencies of the individual sound 15 generated by the soil improvement agent hitting the ground 2 . The computer compares the recorded characteristic specific frequencies with frequencies having amplitude in the waveform of the frequency domain of the sound source as shown in FIG. 4, and identifies the specific frequency component 15 of the sound source. 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 out of the waveforms of the specified frequency range of the identified sound source. there is

In addition, the computer performs inverse Fourier transform on the waveform of the frequency domain of the characteristic frequency components of the separated and extracted sound source, and converts the waveform into a time domain as shown in FIGS. It is configured to operate on the waveform of the region.

Furthermore, this computer filters, separates and extracts characteristic frequency components of the sound source from each of the sound wave waveforms 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 sound source waveforms as shown in FIGS. 5(a), (b), and (c).

In addition, the computer analyzes the phase difference of the time components in the horizontal direction of the waveforms of the specific frequency components of the three sound sources obtained by analyzing the signals from the sensors 7, and generates individual sounds 15. is configured to calculate the time until it reaches each sensor 7 and specify the position 5 of the sound source. The principle and analysis procedure by which the data recording/analyzing device 9 identifies the position 5 of the sound source using a computer will be described in detail in the measurement method.

In addition, the data recording/analyzing device 9 records data on the frequency of the individual sound 15 generated at the contact surface between the ground 2 and multiple types of soil improvement agents with different components and the amplitude intensity data of the frequency component. , a computer compares and analyzes the frequency characteristics and amplitude intensity of specific frequency components of the individual sound 15, and specifies the hardness and material components of the ground 2 in contact.

Furthermore, the data recording/analysis device 9 analyzes the signal of the individual sound 15 generated on the contact surface when the soil improvement agent that is sprayed and constantly moves in the ground 2 collides with the ground 2 by a computer, and analyzes the position of 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 installs the sensors 7a, 7b, and 7c on the back surface of the steel plate 10 provided outside the through-hole 12 at a predetermined position of the drilling rod 3, and A cushioning material 11 is provided between the wall materials of the drilling 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 drilling rod 3. At this time, the sensors 7a, 7b, and 7c are attached to the surface in the same direction as the direction of the injection unit 4 that injects the soil improvement agent, and the sensors 7a, 7b, and 7c are all mounted perpendicular to the wall surface of the excavation rod 3 in the same direction. Set along the direction.

Further, as shown in FIG. 7, the vertical length H ₁ from the injection section 4 to the sensor 7a, the vertical length H ₂ from the injection section 4 to the sensor 7b, and the vertical length from the injection section 4 to the sensor 7c. Measure the direction length _H3 . Also, the distance from the injection part 4 to the ground surface where the excavating rod 3 is excavating is measured.

Next, the operator causes the drilling rod 3 to drill 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 soil improvement agent. Then, the operator activates the sensor 7, the amplifier 8, and the data recording/analyzing device 9 of the underground sound source position measuring system 100, and as shown in FIGS. From the part 4, the ground improvement agent is injected.

Then, the soil improvement agent hits the ground 2, and a sound wave including individual sound 15 is generated from the position 5 of the sound source, which is the contact surface. This sound wave propagates through a solid sound propagation path 6 in the ground 2 and reaches each sensor 7a, 7b, 7c. Sensors 7a, 7b, and 7c detect the sound information of the sound waves including the individual sound 15 of the sound source that has arrived, and the respective sensors 7a, 7b, and 7c transmit signals of the sound information including the individual sound 15 to the wired 13 and the amplifier 8. is received by the data recording/analyzing device 9 via.

The data recording/analyzing device 9 converts the sound source information signal received from the sensor 7 into sound waves of the sound source in the time domain, as shown in FIG. waveforms are detected by overlapped waveforms.

In addition, the data recording/analyzing device 9 uses a computer to perform a Fourier transform on the waveform signal of the time domain of the sound source to obtain a frequency component with the horizontal axis as the frequency component and the vertical axis as the amplitude or phase as shown in FIG. Operate on the waveform of the region.

At this time, the data recording/analyzing device 9 uses a computer to generate a frequency that has an amplitude in the waveform of the sound source in this frequency domain and the contact surface between the pre-recorded soil improvement agent and the ground, as shown in FIG. A specific frequency of the individual sound 15 is compared. Then, with a computer, as shown in FIG. 4, individual sound 15 generated at the contact surface between the pre-recorded soil improvement agent and the ground 2 with respect to the frequency with amplitude in the waveform of the sound source in the specific frequency range The waveform is separated and extracted by filtering so as to take out a specific frequency characteristic of .

Furthermore, the data recording/analyzing device 9 performs inverse Fourier transform on the waveforms of the frequency domain of the characteristic frequency components of the separated and extracted individual sound 15 using a computer, and converts them into the waveforms shown in FIGS. 5(a) and 5(b). ), extracting the waveform of the sound source as shown in (c). Since the waveforms of these sound sources are detected by the three sensors 7a, 7b, and 7c, three of each are extracted. In addition, since the distances between the position 5 of the sound source and each sensor 7 are different in the waveforms of these three extracted sound sources, the difference in propagation time causes a difference in the phase of the time component on the horizontal axis.

Here, 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, and the principle of specifying the position of the soil improvement agent is shown in FIG. will be used to explain.

First, as shown in FIG. 7, let L be a substantially horizontal distance from the position 5 of the sound source to be specified to the injection unit 4 . The distance from the sound source position 5 to the sensor 7a is _L1 , the distance from the sound source position 5 to the sensor 7b is _L2 , and the distance from the sound source position 5 to the sensor 7c is _L3 . Furthermore, 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 time difference (t ₂ −t ₁ ) until the sensor 7b and the sensor 7a detect the individual sound 15 is S ₁ , the time until the sensor 7c and the sensor 7a detect the individual sound 15 (t ₃ −t ₁ ) is _S2 .

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 corresponds to (L ₃ −L ₁ ). Equivalent to.

Therefore, the ratio of _S1 and _S2 is given by 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。

Also, L ₁ , L ₂ , and L ₃ are given by the following equations (2) to (4), respectively, 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/analyzing device 9 calculates the horizontal distance L from the position 5 of the sound source to the injection unit 4 by the formula (5), and measures the horizontal distance L from the calculated position 5 of the sound source to the injection unit 4 in advance. The position 5 of the sound source is specified three-dimensionally from the distance from the injection part 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/analyzing device 9 and proceeds with the work process.

As described above, according to the underground sound source position measurement system 100 of Embodiment 1, 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. Specific frequency components are extracted by filtering to identify the individual sound 15 . Then, the analysis means calculates the phase difference of the individual sounds 15 specified for each of the sensors 7, calculates the respective times until the individual sounds 15 reach the respective sensors 7, and calculates the individual sounds 15. In order to specify the position 5 of the sound source based on the arrival time at each sensor 7, the vertical length from the ejection part 4 to each sensor 7 measured in advance, the depth of the ejection part 4, and the ejection direction, The position of the sound source can be specified three-dimensionally with high accuracy, and in the ground improvement process, by sequentially specifying the position of the sound source generated by the soil improvement agent hitting the ground can be specified with high accuracy. Moreover, since there is no need to separately provide an artificial sound source, the cost of measurement can be reduced.

Further, in this underground sound source position measurement system 100, the data recording/analyzing device 9 filters the sound information detected by the sensor 7 to determine the characteristics of the sound source generated at the contact surface between the soil improvement agent and the ground 2. separates and detects specific frequency components. Therefore, the characteristic frequency of the sound source can be selected and detected without being disturbed by noise in the ground 2, and the position 5 of the sound source can be specified accurately.

Furthermore, in this underground sound source position measuring system 100, the data recording/analyzing device 9 filters sound information successively detected by the sensor 7 to obtain characteristic specific frequency components of the individual sound 15 generated by the sound source. are separated and detected individually, the position of the sound source can be specified with high accuracy.

In this underground sound source position measuring system 100, the data recording/analyzing device 9 performs A/D conversion of sound information detected by a plurality of sensors 7, and the computer analyzes the frequency and phase of the sound source. , Since the position 5 of the sound source in the ground 2 is specified in real time, the operator can confirm the position 5 of the sound source during the injection type ground filling process, and can check the progress of the process (soil improvement range). 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/analyzing device 9 includes a characteristic frequency component 15 of the sound source and a plurality of types of pre-recorded soil improvement agents with different components. In order to compare and analyze the data of the frequency of the individual sound 15 generated at the contact surface between the soil improvement agent and the ground 2, and to specify the hardness and material components of the ground 2 with which the soil improvement agent contacts, the operator can change the work process (improved diameter and specifications) based on the hardness and material components of the ground 2 under construction.

Further, in this underground sound source position measurement system 100, the data recording/analyzing device 9, in the middle of the injection-type ground improvement process, is injected into the ground 2 in the horizontal direction and hits the ground 2. In order to analyze the sound 15 in real time and sequentially identify the boundary position between the soil improvement agent and the ground 2, the worker sequentially confirms the position 5 of the moving sound source and also deals with the individual sound 15 of the moving sound source. can do.

Furthermore, in this 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 drilling rod 3, and between the sensor 7 and the steel plate 10 and the wall material. The cushioning material 11 is provided 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 drilling rod 3, so that the cushioning material 11 is placed in the ground 2 and the drilling rod 3. The vibration of the flowing soil improvement agent can be reduced, the sensor can be prevented from detecting noise, and the collision sound generated when the soil improvement agent hits the ground can be captured more accurately, and the measurement accuracy can be further improved.

Moreover, since the buffer material 11 also serves as a waterproof material, even if the soil improvement agent flowing in the excavation rod 3 comes into contact with the sensor 7, it can be prevented from malfunctioning.
[Embodiment 2 of the invention]
Next, a second embodiment of the invention will be described.

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

FIG. 8 shows Embodiment 2 of the present invention.

An underground sound source position measuring system 100 according to Embodiment 2 is configured to measure an aged underground structure 16 in the ground 2 from the injection part 4 at the tip of the excavation rod 3 of the construction machine 1, as shown in FIG. position 5 of the sound source of the sound generated when the reinforcing agent hits the underground structure 16 in the injection-based structure reinforcement method in which the underground structure 16 is reinforced by injecting a reinforcing agent as a liquid for reinforcing the to specify.

In this second embodiment, the underground sound source position measurement system 100 measures the individual sound generated by the reinforcing agent sprayed at high speed to the extension of the improvement range, which hits the underground structure 16, and the excavation rod 3. The position 5 of the sound source is specified by detecting and analyzing by three sensors 7 arranged in the .

In the data recording/analyzing device 9 of the second embodiment, a plurality of data of the frequency of the individual sound generated by the reinforcing material hitting the underground structure 16 and the amplitude intensity of the frequency component are recorded, and the sensor 7 detects the sound. It is configured to identify whether or not the reinforcing material has reached the underground structure 16 by comparing the frequency of the sound information of the sound wave recorded and the amplitude 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, the operator installs the sensors 7a, 7b, and 7c on the back surface of the steel plate 10 provided outside the through-hole 12 at a predetermined position of the drilling rod 3, and the sensors 7a, 7b, A buffer material 11 is provided between the wall material of the drilling rod 3 and the steel plate 10 so that the sensors 7a, 7b, 7c, the steel plate 10 and the buffer material 11 are flush with the wall surface of the wall material of the drilling rod 3. prepare. At this time, the sensors 7a, 7b, and 7c are attached to the surface in the same direction as the direction of the injection part 4 that injects the reinforcing agent, and the sensors 7a, 7b, and 7c are all mounted on the wall surface of the excavation rod 3 in the same direction, and the vertical direction. set along

At this time, as in the first embodiment, as shown in FIG. 7, the vertical length H ₁ from the injection section 4 to the sensor 7a, the vertical length H ₂ A vertical length _H3 from the injection part 4 to the sensor 7c is measured. Also, the distance from the injection part 4 to the ground surface where the excavating rod 3 is excavating is measured.

Next, the operator causes the drilling rod 3 to drill 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/analyzing device 9 of the underground sound source position measuring system 100, and as shown in FIG. , to inject reinforcing agent.

Then, the reinforcing material hits the underground structure 16 and generates sound waves including individual sounds from the position 5 of the sound source, which is the contact surface of the reinforcing material. This sound wave propagates through a solid sound propagation path 6 in the ground 2 and reaches each sensor 7a, 7b, 7c. The sensors 7a, 7b, and 7c transmit the sound information of the arriving sound waves, and the data recording/analyzing device 9 receives the sound information via the amplifier 8. FIG.

The data recording/analyzing device 9 detects the information signal of the sound wave received from the sensor 7 as a waveform in which the waveform of the sound wave in the time domain overlaps, with the detection time on the horizontal axis and the components such as voltage and current on the vertical axis. .

The data recording/analyzing device 9 also Fourier-transforms the time-domain waveform signal of the sound wave using a computer to calculate a frequency-domain waveform with the frequency component on the horizontal axis and the amplitude or phase on the vertical axis.

At this time, the data recording/analyzing device 9 uses a computer to generate a frequency having an amplitude in the waveform of the sound source in the frequency domain and a pre-recorded individual sound generated at the contact surface between the reinforcing material and the underground structure 16. Compare specific frequencies. Then, the computer generates a characteristic specific sound of the individual sound generated at the contact surface between the pre-recorded reinforcing material and the underground structure 16 with respect to a frequency having an amplitude in the waveform of the sound source in a specific frequency range. The waveforms are separated and extracted by filtering to extract the frequencies, and the waveforms of the nearly matching ones are extracted.

Furthermore, the data recording/analyzing device 9 performs inverse Fourier transform on the frequency domain waveforms of the characteristic frequency components of the separated and extracted individual sounds using a computer, and the horizontal axis is the time component and the vertical axis is the amplitude. Alternatively, the waveform of the phased time component is calculated.

Since the sound source waveforms of these time components are detected by the three sensors 7a, 7b, and 7c, they are extracted three by three. In addition, since the distances between the position 5 of the sound source and each sensor 7 are different in the waveforms of these three extracted sound sources, the difference in propagation time causes a difference in the phase of the time component on the horizontal axis.

The computer of the data recording/analyzing device 9 analyzes the phase difference between the time components of the waveforms of the sound waves of the respective sensors 7, and the position 5 of the sound source generated when the reinforcing material reaches and hits the underground structure 16. The principle for specifying is the same as in the first embodiment.

The operator confirms the position 5 of the sound source specified by the data recording/analyzing 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. Specific frequency components are extracted by filtering to identify individual sounds. Then, the analysis means calculates the phase difference of the individual sound specified for each of the sensors 7, calculates the time required for the individual sound to reach each sensor 7, and calculates the individual sound for each sensor. 7, the vertical length from the injection part 4 to each sensor 7 measured in advance, the depth of the injection part 4, and the injection direction. can be specified three-dimensionally with high accuracy, and in the reinforcement process of the aged underground structure 16, the position of the sound source generated by the reinforcing agent hitting the underground structure 16 is sequentially specified three-dimensionally with high accuracy. be able to. Moreover, since there is no need to separately provide an artificial sound source, the cost of measurement can be reduced.

Further, in this underground sound source position measuring 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 drilling rod 3, and between the sensor 7 and the steel plate 10 and the wall material. The cushioning material 11 is provided 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 drilling rod 3, so that the cushioning material 11 is placed in the ground 2 and the drilling rod 3. Vibration of the flowing reinforcing agent can be reduced, the sensor can be prevented from detecting noise, and the collision sound generated when the reinforcing agent hits the underground structure 16 can be captured with higher accuracy, and the measurement accuracy can be further improved. .

It goes without saying that the first and second embodiments are examples of the present invention, and that the present invention is not limited only to the first and second embodiments.

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

Further, in Embodiments 1 and 2, the sensor 7 is arranged at a position above the injection part 4 of the excavation rod 3, but the excavation rod 3 extends below the injection part 4, and the sensor 7 is placed there. may be placed.

Furthermore, in Embodiments 1 and 2, the sensor 7 and the amplifier 8 are connected by a wire 13 passing through the inner pipe of the excavation rod 3, but the sensor 7 provided on the excavation rod 3 and existing in the ground 2 is It is sufficient that the detected individual sound 15 can be transmitted and received by the amplifier 8 and the data recording/analyzing 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 made into a long wave and transmitted to the amplifier 8 wirelessly.

Further, in Embodiments 1 and 2, one amplifier 8 is provided between the three sensors 7 and the data recording/analyzing device 9. As long as the signal is large enough to be received and analyzed by the device 9 , the amplifier 8 may be omitted, or one amplifier 8 may be connected to each sensor 7 .

Furthermore, in Embodiments 1 and 2, the data recording/analyzing device 9 may be provided with a monitor that displays the position of the specified sound source in the ground.

Furthermore, in the first embodiment, the soil improvement agent in the injection type ground improvement process identifies the position of the sound source generated by hitting the ground, and in the second embodiment, the reinforcing agent in the reinforcement process of the aged underground structure is the underground structure. The underground sound source position measurement system 100 is used to specify the position of a sound source generated by hitting an object. It is also possible to identify the location of other sound sources, such as the location or the location where other machinery is operating.

Furthermore, in Embodiments 1 and 2 described above, the data recording/analyzing device serves as both data recording means and analysis means, but the present invention is not limited to this. may be composed of different devices.

1……Construction machine 2……Soil 3……Excavation rod 4……Injection unit 5……Position of sound source 6……Single sound propagation path 7 (7a, 7b, 7c)……Sensor 8……Amplifier 9…… Data recording/analysis device (data recording means, analysis means)
DESCRIPTION OF SYMBOLS 10... Steel plate 11... Cushioning material 12... Through-hole 13... Wired 15... Individual sound 16... Underground structure 100... System for measuring underground sound source position H ₁ ... From injection part to sensor 7a 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 …… Individual sound generation position from the injection part (sound source ) to approximately horizontal distance

Claims (3)

The individual sound produced by the liquid ejected in the substantially horizontal direction from the injection part of the drilling rod provided at a position vertically dug down to a predetermined depth by boring hits the ground or underground structure is measured by the predetermined sound of the drilling rod. At least two sensors placed at positions sequentially detect sound information including sound waves,
Data recording means specifies the sound information detected by the sensor by frequency components and records the data;
The sound information detected by the sensor is filtered by the data recording means to extract a specific frequency component to specify the individual sound,
An underground sound source position measurement system, wherein the analysis means sequentially identifies the sound source position based on the phase difference of the individual sound identified for each of the sensors and the vertical length between the sensors. . 2. An underground sound source position measurement system according to claim 1, wherein said liquid is a soil improvement agent for soil improvement or a reinforcement agent for reinforcement of underground structures. A through hole is provided in the wall material of the pipe of the drilling rod, a steel plate is provided outside the through hole, the sensor is provided on the back of the steel plate, and a buffer is provided between the sensor and the steel plate and the wall material. 3. The underground sound source location measuring system according to claim 1, wherein a material is provided.

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