JP2015219220A - High-frequency oscillation detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-frequency oscillation detection device capable of easily measuring a depth of a foundation section of an existing underground structure with high accuracy.SOLUTION: A high-frequency oscillation detection device comprises: a sonde section which has a plurality of oscillation sensors to detect high-frequency oscillation; a recording section which records detection results of the plurality of oscillation sensors; and output signal cables which connect respective plurality of oscillation sensors with the recording section and transmit the detection results to the recording section. The sonde section is made up of the plurality of oscillation sensors in a linear arrangement and has a flexible elastic body filling spaces between the oscillation sensors arranged next to each other and between the output signal cables and the respective oscillation sensors in a manner that prevents the oscillation sensors from directly contacting a housing of the sonde section.

Description

  The present invention relates to a high-frequency vibration detection device, and more particularly, to a high-frequency vibration detection device that can be used when determining the depth of a foundation such as an existing underground structure.

  Conventionally, a method using PS logging is known as a method for measuring the depth of a base portion such as an underground structure in its original position (for example, Non-Patent Document 1). In this PS logging, one or two geophones are inserted at an arbitrary depth setting in the borehole, and the vibration waveform by the artificial seismic source is recorded and analyzed.

Uchiyama Narukazu, “Analysis of Elastic Wave Velocity”, Physical Exploration, October 1983, Vol. 36, No. 5, pp. 276-293

  In the conventional PS logging method, the measurement interval in the depth direction is generally as rough as 0.5m to 2m in the borehole, and it is possible to measure the oscillation / vibration time for each depth of 0.25m to 2m. However, there is a limit to find the elastic wave velocity in the shallow subsurface in detail, and it is suitable for grasping the deep boundary of the stratum. A question arises as to whether or not evaluation is possible for the depth survey of the structure foundation in the section.

  An object of this invention is to provide the high frequency vibration detection apparatus which can perform the depth measurement of the foundations, such as an existing underground structure, simply and with high precision.

  In order to achieve the above object, the present invention provides a sonde unit having a plurality of vibration sensors that detect high-frequency vibrations, a recording unit that records detection results of the plurality of vibration sensors, and each of the plurality of vibration sensors. An output signal cable connected to the recording unit and transmitting the detection result to the recording unit, wherein the sonde unit arranges the plurality of vibration sensors on a straight line. A flexible elastic body is disposed between each of the plurality of vibration sensors and the adjacent vibration sensor, and between each of the plurality of vibration sensors and the output signal cable, The vibration sensor is not directly in contact with the housing.

  ADVANTAGE OF THE INVENTION According to this invention, the high frequency vibration detection apparatus which can perform the depth measurement of foundation parts, such as an existing underground structure, simply and with high precision can be provided.

It is a figure which shows the sonde part of the high frequency vibration detection apparatus which concerns on one embodiment of this invention, (a) is a side view, (b) is the rear view seen from the right direction of (a), c) is a plan view, and (d) is a rear view as viewed from the right direction of (c). It is AA sectional drawing of Fig.1 (a). It is BB sectional drawing of Fig.1 (a). It is CC sectional drawing of Fig.1 (a). It is DD sectional drawing of FIG.1 (c). It is a figure which expands and shows the range E of FIG.1 (c). It is the schematic which shows the structure of the high frequency vibration detection apparatus which concerns on one embodiment of this invention. It is a figure which shows an example of the structure of the object measured with the high frequency vibration detection apparatus which concerns on one embodiment of this invention, (a) is a front view (underground cross section), (b) was seen from the sky It is a top view. It is a figure which shows the depth measurement and analysis result by the high frequency vibration detection apparatus which concerns on one embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail.

  By the way, according to the present invention, a sonde portion (48 vibration sensors are arranged on a straight line at an equal interval of 3 cm) fixedly installed in a borehole adjacent to a base portion of an existing underground structure or the like is used. By using an artificial seismic source located on the exposed part of the structure's surface, the high frequency component waveform of the vibration caused by the artificial seismic source can be detected and recorded at once, and the underground structure can be easily created in situ. It is possible to perform a depth measurement of the foundation.

  The elastic wave velocity, which is the propagation characteristic of the ground and the structure, is an important parameter in determining the depth of the foundation of an existing underground structure. The elastic wave velocity, which is a propagation characteristic parameter of the ground, is estimated by measuring the time from oscillation (vibration) by the artificial seismic source to vibration reception.

  The present invention provides a highly accurate measurement method while simultaneously recording vibration waveforms by a plurality of vibration sensors at the original position and displaying a visible image. According to the present invention, a more reliable elastic wave velocity is obtained, and the boundary depth of the foundation portion of the existing underground foundation structure is judged and evaluated in detail. As a result, when maintaining and inspecting structures and the like, high expectations are also placed on in-situ quality control and cost reduction. In addition, a survey of the foundations of existing structures, etc. is also required when examining the durability and seismic resistance, and the survey is likely to increase year by year.

  1A and 1B are diagrams showing a sonde part of a high-frequency vibration detecting device according to an embodiment of the present invention, wherein FIG. 1A is a side view and FIG. 1B is a rear view as viewed from the right side of FIG. (C) is a plan view, and (d) is a rear view seen from the right direction of (c).

  FIG. 2 is a cross-sectional view taken along line AA in FIG.

  FIG. 3 is a cross-sectional view taken along the line BB in FIG.

  4 is a cross-sectional view taken along the line CC of FIG.

  FIG. 5 is a sectional view taken along the line DD of FIG.

  FIG. 6 is an enlarged view showing a range E in FIG.

  FIG. 7 is a schematic diagram showing the configuration of the high-frequency vibration detection device according to one embodiment of the present invention.

  The high-frequency vibration detection apparatus according to the present embodiment includes a sonde unit 100 and a recording unit that records data detected by the sonde unit 100 (see FIG. 7).

  The sonde unit 100 has a configuration in which 48 vibration sensors 1, an elastic body, a support body, and a protection body are assembled and integrated.

  Each of the plurality of vibration sensors 1 is formed inside the elastic body, the support body, and the protection body, and is arranged in a straight horizontal direction so that the distance between them is equal to 3 cm.

  The elastic body is composed of a glass fiber sheet portion 2, a silicon rubber molding portion 3, a metal plate portion 4 with a male screw, and a female screw metal projection portion 5. The glass fiber sheet part 2 is superimposed on the silicon rubber molding part 3.

  The support body is formed of elastic members, and the glass plate is formed by bonding the vibration sensor 1 and the metal plate portion 4 with the male screw in advance, and the metal plate portion 4 with the male screw and the metal projection portion 5 with the female screw. The vibration sensor 1 is attached by tightening support with the male screw of the metal plate portion 4 with male screw and the female screw of the metal projection portion 5 with female screw being screwed together.

  The protector is composed of a vibration sensor 1, an elastic body, a metal member that protects the support, and a raw rubber member, and is formed so as not to be in direct contact with the vibration sensor 1. The tip of the metal protrusion 5 of the elastic body is formed in an arc shape and can be pushed in by the elasticity of the silicon rubber molding portion 3.

  In the in-situ position, it is important to ensure adhesion between the sonde portion 100 and the borehole wall. As a method, a raw rubber tube packer 17 is arranged at a position where the longitudinal direction of the sonde portion 100 is divided into three and opposite to the female screw metal projection 5, and the raw rubber tube packer 17 goes in the longitudinal direction of the sonde portion 100. A method is employed in which air is blown out from the air outlet 10 of the air pipe portion 9 which is a spanning tube, and the raw rubber tubes 11 and 12 are inflated to press the sonde portion 100 against the borehole wall. Further, the vibration sensor 1 is supported and fixed by a highly flexible silicon rubber molding portion 3 and a glass fiber sheet 2 and has a flexible structure, so that the unevenness of the irregularity of the borehole wall is compensated for and vibration is generated. The pressure-bonding property of the entire sensor 1 is improved, and homogeneous data can be collected.

  The recording unit includes a recording unit 18 and a visible image output monitor 19. The recording unit 18 simultaneously detects and records the output signals of the 48 vibration sensors 1 of the sonde unit 100, for example, a personal computer (PC). Waveform recording can be confirmed by the visible image monitor 19.

  The waveform recording of the output signals of the 48 vibration sensors 1 of the sonde unit 100 has a maximum recording length of 40 mSec (milliseconds) secured simultaneously by sampling at a maximum of 10 μSec (microseconds). There are two types of data recording formats: normal and pre-trigger. Depending on the measurement method, it is possible to select to sample either when the trigger occurs or when it starts up before the trigger occurs. Yes. The data recording capacity is stored and secured as a maximum of 4096 digital data per component in each mode. Each channel is provided with an attenuator and an amplifier (maximum amplification factor 100 times), and can be connected to a preamplifier having various output amplitudes. In addition, it has a run-time processing tool for managing recorded data.

  As an investigation method for measuring the depth of an underground structure foundation according to the present invention, an artificial seismic source that strikes the structure ground with a hammer 21 is applied, and the inside of a borehole as close as possible to the structure foundation is applied. The probe 100 is inserted from the end 100b side, and a plurality of vibration sensors (48, 3 cm equally spaced) are brought into close contact with the boring hole wall via the projection 5 by the air packer 17 to detect the impact vibration waveform collectively. To do. For recording the waveform of the impact vibration, the depth of the structure base can be accurately evaluated by the data recorder 18 capable of simultaneously measuring high-frequency components with high resolution and high sampling. Further, in the present invention, a measurement boring hole for inserting the sonde unit 100 is indispensable, but an air hose that supplies air for inflating the output signal cable 15 of the sonde unit 100, the recorder 18, and the raw rubber tubes 11 and 12 is used. 16 and the air pump 20 are connected to each other, and it is only necessary to hit the hammer while checking the waveform on the visible image monitor 19, and the recording device 18 is provided with a run time processing tool for the recorded data so that the visible image can be seen in the original position. By drawing the speed travel time curve on the monitor, it is possible to easily determine the approximate depth of the structure base (inflection point of elastic wave velocity), making it possible to conduct cost-effective surveys. . The timing (trigger) of hitting with the hammer 21 is transmitted to the recorder 18 via the trigger line 22.

  As shown in FIGS. 1A to 1D, the sonde portion 100 of the high-frequency vibration detection device of the present embodiment has a total length of about 1700 mm in the longitudinal direction (insertion direction into the boring hole), an outer diameter long side φ65 mm, It has a short diameter of φ50 mm.

  The configuration of the sonde unit 100 will be described. Forty-eight vibration sensors 1, elastic bodies and support bodies 2, 3, 4, 5 and protective bodies 6, 7, 8 are assembled and integrated. In addition, each of the parts 9, 10, 11, 12, 13, 16, and 17 relating to the crimping part of the sonde part 100, the fixing screw 14 relating to the housing and the like, and the output signal cable 15 are formed.

  The housing portion 6 is formed by welding side plate members 6a and 6b which are also extended in the longitudinal direction of the sonde portion 100 and curved toward the vibration sensor 1 on both sides of the bottom plate member 6c extending in the longitudinal direction of the sonde portion 100. The

  The housing portion 7 is formed by welding side plate members 7 a and 7 b that are also extended in the longitudinal direction of the sonde portion 100 and curved toward the vibration sensor 1 on both sides of the bottom plate member 7 c that extends in the longitudinal direction of the sonde portion 100. The

  The housing part 6 and the housing part 7 are fastened by a fixing screw 14, and a housing cover part 8 is put on the outside thereof.

  The vibration sensor 1 is formed inside the elastic body, the support body, and the protection body of the sonde section 100, and is arranged in a horizontal direction at three equal intervals on a straight line in the cylindrical frame of the silicon molding section 3, The elastic body is composed of a first elastic body and a second elastic body.

  The first elastic body is overlapped by the glass fiber sheet portion 2 shared by the vibration sensor 1 as a whole and the silicon rubber molding portion 3. On the other hand, the second elastic body includes a metal plate portion 4 with a male screw and a metal projection portion 5 with a female screw for each vibration sensor 1. The support is composed of these elastic bodies, and is bonded in advance to the vibration sensor 1 and the metal plate portion 4 with the female screw, and the glass fiber sheet portion 2 is clamped by the metal projection 5 with the female screw, and vibration is applied. The sensor 1 is supported and fixed.

  The metal threaded metal projection 5 is formed in an arc shape and can be pushed in by the flexibility of the glass fiber sheet portion 2 and the silicon rubber molding portion 3.

  The protective body is composed of metal housing parts 6 and 7 that protect the entire vibration sensor, the elastic body, and the support body, and a housing cover part 8 made of raw rubber on the outermost periphery. It is formed so that there is no contact. The metal housing parts 6 and 7 are configured to be separable and are fastened by a plurality of fixing screws 14.

  The vibration sensor 1 used is a moving coil type speedometer having an outer diameter of φ19 and a natural frequency of 28 Hz. Each of the plurality of sensors 1 is housed in the cylindrical frame of the silicon rubber molding portion 3, and the output signal cable 15 is Embedded in the silicon rubber molding part 3, connected to the output signal terminal 1 a of each sensor 1, and the end part 100 a of the sonde part 100 (when the sonde part 100 is inserted into the boring hole so as to avoid buffering between the vibration sensors 1. It is inserted to the top.

  On the back side of the 48 vibration sensors 1, air packer portions 17 are provided at three locations in the central portion that divide them into four equal parts, and the metal projections 5 with elastic female threads are placed at a constant pressure (0.15 MPa to 0). .. 20 MPa), bore hole wall crimping portions 11 and 12 made of a raw rubber tube that can be crimped to the sidewall of the bore hole are arranged in the protective body as a fixing device. In FIG. 2, an air filling state 13 in which air is supplied to the bored hole wall crimping portions 11 and 12 is indicated by a broken line.

  Next, data recording according to this embodiment of the high-frequency vibration detection apparatus will be described with reference to the outline of the measurement method shown in FIG.

  When the foundation part of the existing structure is exposed to the ground, a bored hole is provided in the vicinity thereof, the sonde part 100 is inserted into the hole, and units of 48 vibration sensors 1 (3 cm equally spaced) are provided. When the predetermined depth is reached, air is supplied to the air pipe section 9 from the ground pump 20 via the air hose 16, and air is blown out from the air outlet 10 of the air pipe section 9 to inflate the air packer 17, The tip of the female screw metal projection 5 is fixed by crimping to the side wall of the boring hole.

  Next, the exposed upper surface of the structure base is vibrated by the hammer 21 for impact, and the vibration waves generated at this time are transmitted to the structure and the ground by each of the 48 vibration sensors 1 and output. In this method, measurement is performed by the recording units 18 and 19 on the ground through the signal cable 15 and the trigger line 22 for detecting the shot time.

  Data recording by this measuring method is performed by a conventional general PS logging data recording device using a recording device 18 and a visible image monitor 19 of a personal computer (PC) for output signals from each of the 48 vibration sensors 1. The sampling interval is about 5 times higher than that of 48, and the data from 48 vibration sensors 1 are A / D converted at a time of 10 μSec (microseconds) simultaneously by batch detection and have a maximum recording length of 40 mSec (milliseconds). The memory can be saved by recording, and the waveform recording can be monitored.

  There are two types of data recording formats. In the normal format, data can be recorded by starting sampling as soon as a trigger occurs. In the other pre-trigger format, when sampling is started simultaneously with activation and a trigger is generated, data from before the trigger is generated can be recorded. The data recording capacity of each format is a maximum of 4096 digital data per vibration sensor component. Each channel has an attenuator and an amplifier (maximum amplification factor of 100), and can be connected to a preamplifier having various output amplitudes. Furthermore, a run-time processing tool for management with respect to data recording at the original position is provided, and the approximate depth of the structure foundation can be determined.

  As for the analysis method of the recorded data, as shown by the reference numerals in FIG. 7, the depth of the structure base is determined by the elastic wave velocity (V2, V3) propagating through the ground and the elastic wave velocity (V1) propagating through the structure. Due to the difference, the determination is made in units of 3 cm of the interval between the vibration sensors 1 and evaluated. The evaluation of the depth of the upper and lower ends of the foundation is obtained from the following equations based on Snell's law.

  The upper end depth is estimated as follows: X1 = A × tan θ1, where sin θ1 = V2 / V1, and Z1 = Z1′−X1.

  The lower end depth is estimated as follows: X2 = A × tan θ2, and Z2 = Z2′−X2, where sin θ2 = V3 / V1.

  Next, the measurement results in the actual configuration will be described.

  In-situ, a depth survey of the bottom plate portion of the L-type retaining wall using the high-frequency vibration detection device of the present example was conducted, and the details of the depth of the foundation bottom plate portion were examined. FIG. 8 is a diagram showing the shape of the bottom plate portion of the L-shaped retaining wall to be measured. (A) is a front view (underground cross section), (b) is a plan view seen from above.

  In carrying out the measurement, a boring hole (outer diameter φ76 mm, depth L = 3 m) into which the sonde portion 100 was inserted was excavated. The ground of the survey area consists of loam layers from the ground surface to a depth of 3 m.

  The L-type retaining wall to be investigated has a height of H2000 mm, W2005 mm, and D1300 mm, and a foundation bottom is embedded in GL-1612 mm. The boring hole is located near the center of the retaining wall (bottom of the bottom plate) and at a position 112 mm away from the end of D1300 mm. Regarding the measuring method, the sonde part 100 is inserted into the borehole, and the vibration sensor at the top of the sonde part 100 is fixed in position by the air packer 17 at a depth of 0.8 m. The vibration was performed by hammering.

  FIG. 9 shows an impact vibration waveform recorded by the high-frequency vibration detector of this embodiment. In the figure, an elastic wave velocity curve is analyzed for the waveform data using a management travel time processing tool, and an example of the result is also shown. ch. 1 is a signal detected by the vibration sensor 1 at the top. 48 is a signal detected by the vibration sensor 1 at the bottom (depth GL-0.8 m to GL-2. 21 m).

  The recorded data obtained in this embodiment is a 48-component signal (output signal from each of 48 vibration sensors 1) recorded by batch detection and simultaneously A / D converted at a sampling interval of 10 μSec (microseconds). The recording length was 40 mSec (milliseconds).

  The data was recorded in pre-trigger mode, where sampling was started at the same time as the start and a trigger occurred, and data from before the trigger occurred can be recorded. The recording capacity of all components was 4096 digital data per component of the output signal from the vibration sensor 1. The attenuator provided in the recorder 18 was not used, and the amplification factor of the amplifier was 100 times.

  According to FIG. 9, the elastic wave average velocity (V2) of the upper layer ground obtained a result showing 460 m / sec, and the elastic wave average velocity (V3) of the lower layer ground obtained a result showing 864 m / sec. The inflection points (Z1 ', Z2') can be confirmed at 1.46 m and 1.67 m for the depth (measurement depth) of the vibration sensor whose measurement running time is disturbed by elastic waves from the base of the L-shaped retaining wall. The actual depth of the L-shaped retaining wall was obtained by an analysis method applying Snell's law from the elastic wave velocity and inflection point of the ground obtained here.

  Table 1 shows the measurement / analysis results. According to this result, the upper end of the foundation bottom was 1.392 m and the lower end was 1.612 m. In this example, when the average elastic wave velocity (V1) of concrete was assumed to be 3500 m / sec, the depths of the upper end and the lower end were estimated with an accuracy of approximately 3 cm to 5 cm.

As described above, the application of the measurement and analysis method using the high-frequency vibration detection device according to the present invention is performed by excavating a boring hole as close as possible to the structure base portion, in particular, the depth of the lower end of the base portion. The effectiveness of the detailed survey was shown.

  In addition, it is indispensable to drill a plurality of boring holes in the original position, but by establishing an easy drilling method for boring holes, it is possible to quickly and easily determine and evaluate the foundation depth of structures, Furthermore, it has been shown that by providing the high-frequency vibration detection device of the present invention, cost-effectiveness is high and high-precision measurement / analysis can be performed.

  That is, using the high-frequency vibration detection device of the present invention, it was confirmed in the examples that the depth of the structure base portion of the L-type retaining wall is required in detail. The results of this example clearly show inflection points on the waveform record that disturb the measurement travel time due to elastic waves from the foundation of the L-shaped retaining wall, and the elasticity of the upper and lower layers obtained from this waveform record. It was confirmed that the actual depth of the upper and lower ends of the L-type retaining wall foundation can be estimated with an accuracy of approximately 3cm to 5cm by an analysis method that applies Snell's law with the average elastic wave velocity of the concrete assuming the wave average velocity. .

  Here, a method for manufacturing the sonde portion of the high-frequency vibration detection device according to the embodiment of the present invention will be described.

  The procedure for manufacturing and assembling the sonde is made up with the production of the silicon molding part 3 as one, the arrangement of the plurality of vibration sensors 1 as two, and the exteriors of the housing parts 6, 7, and 8 as three.

  The detailed assembly procedure and points to be noted in each of the above parts are as follows.

(1) At the time of production of the flexible silicon molding part 3, the cylindrical holes of the shape of the plurality of vibration sensors 1 are arranged on a straight line with an exact interval of 3 cm, and the glass fiber sheet part 2 is placed in the silicon molding part 3 In order to intervene, a flat surface that supports the plurality of vibration sensors 1 is formed and the output signal cable 15 is not directly touched by the plurality of vibration sensors 1.
(2) When mounting and supporting a plurality of vibration sensors 1 on the glass fiber sheet portion 2, after curing the silicon rubber molding portion 3, the plurality of vibration sensors 1 are previously bonded to the male screw metal plate portion 4 and then molded with silicon. Each vibration sensor 1 is pushed into the cylindrical hole of the portion 3 and the male screw and the female screw metal protrusion 5 of the male screw metal plate portion 4 projecting on the flat surface of the glass fiber sheet portion 2 are screwed into a form without loosening.
(3) After the plurality of vibration sensors 1 are arranged and supported on the silicon molding part 3, the output signal cables 15 (polarity ±) are soldered to the output terminals 1a (polarity ±) of the respective vibration sensors 1, There is no difference between the signal polarity (±) and the channel number order (ch.1 to ch.48).
(4) At the time of molding the metal cover (housing part 6, housing part 7) and rubber cover (housing cover part 8) of the housing part which is a protector of the plurality of vibration sensors 1, it matches the shape of the silicon rubber molding part 3. Therefore, it is necessary to make a caution such as making a metal cover and a rubber cover fitted to the metal cover so as not to directly contact the plurality of vibration sensors 1.

  The sonde portion of the high-frequency vibration detection device according to one embodiment of the present invention is configured so that maintenance can be easily performed. By removing the fixing screws of the housing portions 6 and 6, the silicon molding portion 3 can be removed. The elastic body and the support can be easily disassembled individually by loosening and removing the female screw metal protrusion 5 that supports and fixes the plurality of vibration sensors 1 inside the glass fiber sheet 2.

  Hereinafter, the present invention will be described again.

  The present invention is a high-frequency vibration detection apparatus comprising a sonde unit having a plurality of vibration sensors for detecting high-frequency vibrations, and a recording unit for recording the detection results of the plurality of vibration sensors, A plurality of vibration sensors are arranged on a straight line, and an elastic body is arranged between each of the plurality of vibration sensors and an adjacent vibration sensor.

  Further, the present invention includes a sonde unit and a recording unit that records data detected by the sonde unit, and the sonde unit includes 48 vibration sensors, an elastic body, a support body, and a protection body. The 48 vibration sensors are formed of the elastic body, the support body, and a protection body, and are arranged in a straight line in a horizontal direction at regular intervals of 3 cm. The glass fiber sheet part, the silicon rubber molding part, the metal plate part with male screw, and the metal projection part with female screw are formed, and the glass fiber sheet part is superimposed on the silicon rubber molding part. The support body is formed of each member of the elastic body and is adapted to fix the vibration sensor in a straight line, and the vibration sensor and the metal plate portion with the female screw are bonded in advance. And the metal with the female screw The glass fiber sheet portion is sandwiched between protrusions, and the vibration sensor is attached by tightening and fixing. The protective body is a metal member and a raw rubber cover portion that protect the elastic body and the support body. It is configured.

  The metal protrusion of the elastic body is formed in an arc shape and can be pushed in by the elasticity of the silicon rubber molding portion.

  The recording unit is a digital data recording unit that collectively detects output signals of the 48 vibration sensors, and the recording unit is connected to the output signal cables of the 48 vibration sensors of the sonde unit. It is equipped with an analog / digital signal converter (A / D converter), amplifier, attenuator, and personal computer (PC) for each channel. The wave velocity can be obtained.

  In the present invention, the 48 vibration sensors use a moving coil type speedometer having an outer diameter of φ19 mm and a natural frequency of 28 Hz, and are housed in a silicon rubber molding frame having an inner diameter of φ19 mm and are used as output terminals. A signal cable for detecting vibration is connected, and the signal cable is inserted into and penetrated into four parts while avoiding a buffer between vibration sensors in the silicon rubber molding part of the elastic body. The speed output of the frequency component higher than the natural frequency of the moving coil type speedometer is detected.

  Further, in the present invention, the elastic body includes a first elastic body member and a second elastic body member, and the first elastic body member includes the glass fiber sheet portion with respect to the vibration sensor and the silicon On the other hand, the second elastic body member is composed of the male screw-attached metal plate portion and the female screw-attached metal projection portion for each of the vibration sensors, and the male screw-attached metal. The plate part is bonded to the vibration sensor.

  Further, in the present invention, on the back side of the 48 vibration sensors, air packer portions are provided at three locations in the central portion that equally divides them into four parts, and the metal protrusions with the female thread of the elastic body are provided with a constant pressure (0.15 MPa A boring hole wall crimping part made of raw rubber tube that can be pushed in at ~ 0.20 MPa) is arranged in the protective body as a fixing device.

  Further, according to the present invention, the protector includes a first protector and a second protector, and the first protector forms a metal housing portion for the vibration sensor and the fixing device. The second protector is a housing cover portion made of a raw rubber tube that covers the entire first protector, and the protector is molded so as not to directly contact the vibration sensor.

  In the present invention, the recording device collectively detects output signals from the 48 vibration sensors, and at the same time a maximum recording time of 40 mSec (milliseconds) at a sampling interval of 10 μSec (microseconds) and a recording length of a personal computer (PC). Recording is performed while checking the visual image monitor. There are two types of data recording formats: normal and pre-trigger. The normal format starts sampling as soon as a trigger occurs, and the data is recorded. One pre-trigger format starts sampling at the same time as activation, and when a trigger occurs, the data from before the trigger occurs is recorded. The recording capacity is up to 4096 digital data per vibration sensor component, and it can be connected to preamplifiers with various output amplitudes. It is now possible to perform signal processing via an analog / digital signal converter (A / D converter) for each channel and store the digital data on the hard disk (HDD) of a personal computer (PC). In addition, the recorded data waveform can be confirmed by a visible image monitor of a personal computer (PC).

  In addition, the present invention is provided with travel time processing tool software for managing recorded data, in which the approximate depth of the structure foundation can be determined at the original position.

  The high-frequency vibration is a vibration in which a high-frequency component generated by an artificial seismic source that hits a structure exposed on the ground is detected by the 48 vibration sensors in the sonde. This vibration is obtained by simply using the high-frequency vibration detection device such as a sonde part fixedly installed in a boring hole close to the foundation part of an existing underground structure, etc. Determine the depth of the foundation of the existing underground structure.

In the present invention,
1. A sonde unit having a plurality of vibration sensors for detecting high-frequency vibrations, a recording unit for recording detection results from the plurality of vibration sensors, and connecting each of the plurality of vibration sensors and the recording unit to obtain the detection results. An output signal cable for transmission to the recording unit, and a high-frequency vibration detection device comprising:
The sonde portion is formed by arranging the plurality of vibration sensors on a straight line,
A flexible elastic body is disposed between each of the plurality of vibration sensors and the adjacent vibration sensor and between each of the plurality of vibration sensors and the output signal cable, and the housing of the sonde unit The vibration sensor was not touched directly.
Because it is a high-frequency vibration detection device characterized by
It is possible to provide a high-frequency vibration detection device that can easily and accurately measure the depth of a foundation such as an existing underground structure.
The present invention also provides
2. 1. The high-frequency vibration detection device according to claim 1,
The sonde portion is inserted into a boring hole,
The vibration sensor detects vibration around the boring hole through a metal projection that contacts the side wall of the boring hole.
A high-frequency vibration detector characterized by the above.
The present invention also provides
3. 2. The high-frequency vibration detection device according to claim 1,
The sonde portion has an air packer on the back side of the metal protrusion,
Supplying the air to the air packer causes the air packer to swell and cause the metal protrusion to be crimped to the side wall of the boring hole;
A high-frequency vibration detector characterized by the above.

  The embodiments of the present invention are not limited to the individual embodiments described above, and any combination of elements of the individual embodiments is included in the present invention, and various modifications that can be conceived by those skilled in the art are also included. Thus, the effects of the present invention are not limited to the above-described contents. That is, various additions, modifications, and partial deletions can be made without departing from the concept and spirit of the present invention derived from the contents defined in the claims and equivalents thereof.

  The high-frequency vibration detection device according to the present invention can be used when determining the depth of the foundation portion of an underground structure or the like. It is applicable to any device that performs detection.

1: Vibration sensor (moving coil type natural frequency: 28Hz)
2: Glass fiber sheet (made of double glass fiber)
3: Silicon rubber molding part 4: Metal plate part with male screw (made of SUS)
5: Metal protrusion with female screw (made of SUS)
6: Vibration sensor, silicon molded housing (SUS)
7: Housing part of the hole wall crimping part (manufactured by SUS)
8: Housing cover (raw rubber φ50mm, t1.0mm)
9: Air pipe (aluminum φ16mm)
10: Air outlet 11: Hole wall crimping part (Raw rubber φ16mm, t1.0mm)
12: Hole wall pressing part (raw rubber φ16mm, t1.0mm)
13: Air filling state (0.15 to 0.20 Mpa)
14: Housing fixing screw (M3)
15: Output signal cable (φ6mm)
16: Air hose 17: Air packer 18: Recorder (A / D converter, amplifier, attenuator)
19: Visible image output monitor 20: Air pump 21: Blow hammer 22: Trigger line 100: Sonde part 100a, 100b: End part of the sonde part V1: Elastic wave average velocity of structure (m / sec)
V2: Elastic wave average velocity of upper ground (m / sec)
V3: Elastic wave average velocity of the lower ground (m / sec)
A: Boring hole and structure proximity distance (m)
Z1: Structure top depth (m)
Z2: Bottom depth of structure (m)
Z1 ': Upper inflection point depth (m)
Z2 ': Lower inflection point depth (m)
X1: Upper end refractive depth (m)
X2: Bottom refraction depth (m)
θ1: Upper refraction angle (degrees)
θ2: Bottom refraction angle (degrees)
L: Depth of borehole (m)
φ: Drilling diameter of borehole (mm)

Claims (3)

A sonde unit having a plurality of vibration sensors for detecting high-frequency vibrations, a recording unit for recording detection results from the plurality of vibration sensors, and connecting each of the plurality of vibration sensors and the recording unit to obtain the detection results. An output signal cable for transmission to the recording unit, and a high-frequency vibration detection device comprising:
The sonde portion is formed by arranging the plurality of vibration sensors on a straight line,
A flexible elastic body is disposed between each of the plurality of vibration sensors and the adjacent vibration sensor and between each of the plurality of vibration sensors and the output signal cable, and the housing of the sonde unit The vibration sensor was not touched directly.
A high-frequency vibration detecting apparatus characterized by that. The high-frequency vibration detection device according to claim 1,
The sonde portion is inserted into a boring hole,
The vibration sensor detects vibration around the boring hole through a metal projection that contacts the side wall of the boring hole.
A high-frequency vibration detecting apparatus characterized by that. The high-frequency vibration detection device according to claim 2,
The sonde portion has an air packer on the back side of the metal protrusion,
Supplying the air to the air packer causes the air packer to swell and cause the metal protrusion to be crimped to the side wall of the boring hole;
A high-frequency vibration detecting apparatus characterized by that.