Slime determination device and slime determination method

Abstract

To provide a slime determination device and a slime determination method for efficiently determining a slime sedimentation state of a hole bottom.SOLUTION: The slime determination device A1 uses a management device 20 including a measurement information storage part 22 and a control part 21 for analyzing the detection waveform. A measurement information storage part 22 records a plurality of detection waveforms when a scale tape M1 is driven to a pile hole H1 before slime treatment and after slime treatment from a sensor device 10 attached to the scale tape M1 capable of reaching a hole bottom H2 of the pile hole H1 of a cast-in-place concrete pile. A control part 21 extracts a plurality of peak ranges in detection waveforms before slime treatment and after slime treatment, and outputs a statistical processing result of a frequency analysis result of the plurality of peak ranges.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a slime determination device and a slime determination method for determining the slime settling state at the bottom of a pile hole of a cast-in-place concrete pile, for example. [Background technology]

[0002] When constructing cast-in-place concrete piles using the earth drill method with stabilizer, the excavation waste and the fine sand and fine soil suspended in the stabilizer settle as slime at the bottom of the pile hole. If slime remains at the bottom of the hole when the concrete is poured, it can be entrained and the quality of the concrete in the pile body can deteriorate, or the pile tip's bearing capacity can be impaired because slime is trapped between the pile and the tip of the ground. For this reason, in normal construction, hole bottom treatment (slime treatment) is carried out to remove the slime before pouring the concrete.

[0003] This method of determining the slime settling condition involves lowering a measuring tape with a weight attached to the bottom of the hole, measuring the depth of the top surface of the slime from the feel transmitted to the hand when the weight comes into contact with the top surface of the slime, and determining the slime settling condition before and after bottom-hole treatment.

[0004] Furthermore, technology for checking the settling status of slime at the bottom of a hole has also been studied (see, for example, Patent Document 1). The technology disclosed in this document checks the settling status of slime at the bottom of a pile hole for a cast-in-place concrete pile. A sensor device attached to a measuring gauge that can reach the hole bottom acquires a detected waveform when the measuring gauge is hammered into the hole bottom. The detected waveform is then analyzed to determine the settling status of the slime. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2023-131839 Summary of the Invention [Problem to be solved by the invention]

[0006] However, with the technology described in Patent Document 1, it may not be possible to determine the settling state of slime by analyzing the detected waveform. For example, when comparing the detected waveform before slime treatment with the detected waveform after slime treatment, the difference may not be clear depending on the location. [Means for solving the problem]

[0007] The slime determination device for solving the above problem includes a measurement information storage unit that records multiple detected waveforms from a sensor device attached to a long object that can reach the bottom of a pile hole for a cast-in-place concrete pile before and after slime treatment when the long object is driven into the bottom of the hole, and a control unit that analyzes the detected waveforms.The control unit then extracts multiple peak ranges from the detected waveforms before and after slime treatment recorded in the measurement information storage unit and outputs the frequency analysis results of the multiple peak ranges. [Effects of the Invention]

[0008] According to the present disclosure, the slime settling condition at the bottom of the hole can be efficiently determined. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an explanatory diagram of a system according to an embodiment. [Figure 2] FIG. 2 is an explanatory diagram of a hardware configuration of the embodiment. [Figure 3] FIG. 1 is an explanatory diagram of a sensor device according to an embodiment. [Figure 4] FIG. 10 is an explanatory diagram of a processing procedure of slime determination processing according to an embodiment. [Figure 5] 1A and 1B are explanatory diagrams of the processing procedure of slime determination processing in an embodiment, where FIG. 1A is an explanatory diagram before slime processing, and FIG. 1B is an explanatory diagram after slime processing. [Figure 6]10A and 10B are explanatory diagrams of the frequency characteristics of the measurement results of an embodiment, where (a) is an acceleration diagram, (b) is a diagram of identifying the peak range, and (c) is a diagram of extracting the peak range before slime processing. [Figure 7] 10A and 10B are explanatory diagrams of the frequency characteristics of the measurement results of an embodiment, where (a) is the peak range extracted before slime treatment, and (b) is an explanatory diagram of the frequency analysis results before slime treatment. [Figure 8] An explanatory diagram of the frequency characteristics of the measurement results of an embodiment, where (a) is the identification of the peak range after slime processing, (b) is the peak range extracted after slime processing, and (c) is an explanatory diagram of the frequency analysis results after slime processing. [Figure 9] FIG. 10 is an explanatory diagram of a confirmation screen according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a specific embodiment of a slime determination device and a slime determination method will be described with reference to FIGS. As shown in Figure 1, in this embodiment, the settling state (presence or absence) of slime SL1 at the hole bottom of a pile hole H1 of a cast-in-place concrete pile is determined. The pile hole H1 is filled with a stabilizing liquid containing bentonite to stabilize the hole wall when excavated.

[0011] When checking the depth of the pile hole H1, a measuring tape M1 with a scale is used. The measuring tape M1 is a planar tape measure (long object) of a length (for example, 10 m to 100 m) that can reach the hole bottom H2. A weight W1 is hung from the tip of this measuring tape M1. Note that the long object is not limited to the measuring tape M1, as long as it is long enough to reach the hole bottom H2 and vibrates when it comes into contact with it. For example, it may be a cord or a rod-like object.

[0012] In this embodiment, a slime determination device A1 is used, which further includes a sensor device 10, an amplifier AP1, and a management device 20. The sensor device 10 is attached to the end of the measurement tape M1. Details of the sensor device 10 will be described later.

[0013] The sensor device 10 is connected to the management device 20 via a communication line and an amplifier AP1. (Hardware configuration description) 2, the hardware configuration of the information processing device H10 constituting the management device 20 will be described. The information processing device H10 includes a communication device H11, an input device H12, a display device H13, a storage device H14, and a processor H15. Note that this hardware configuration is an example, and it can also be realized by other hardware.

[0014] The communication device H11 is an interface that establishes a communication path with other devices and transmits and receives data. The input device H12 is a device that accepts input of various information, such as a mouse, a keyboard, etc. The display device H13 is a display or the like that displays various information.

[0015] The storage device H14 is a storage device that stores data and various programs for executing various functions of the management device 20. The processor H15 uses programs and data stored in the storage device H14 to control each process in the management device 20. Examples of the processor H15 include a CPU and an MPU. The processor H15 loads programs stored in a ROM or the like into a RAM and executes various processes for each process.

[0016] The processor H15 is not limited to a processor that performs all of the processing it executes using software. For example, the processor H15 may include a dedicated hardware circuit (e.g., an application-specific integrated circuit (ASIC)) that performs hardware processing for at least part of the processing it executes.

[0017] (System Configuration) Next, each function of the slime determination device A1 will be described. 3, the sensor device 10 has accelerometers 12, 13, and 14 fixed to a plate material 11 such as an acrylic plate. The plate material 11 is detachably attached to the surface of a measure tape M1 by a fixture ST1 such as a turn clip. In this embodiment, if the direction perpendicular to the surface of the measure tape M1 is the X-axis direction, the width direction of the measure tape M1 is the Y-axis direction, and the length direction of the measure tape M1 is the Z-axis direction, the sensor device 10 is disposed in the YZ plane.

[0018] Accelerometer 12 measures an acceleration waveform (vibration waveform) in the Z-axis direction. Accelerometer 13 measures an acceleration waveform (vibration waveform) in the Y-axis direction. Accelerometer 14 measures an acceleration waveform (vibration waveform) in the X-axis direction. Measurement signals (time-series acceleration data) measured by each of accelerometers 12 to 14 are transmitted via cable C1. This cable C1 is bundled with a fixture ST2 such as a turn clip and fixed to a measuring tape M1.

[0019] 1, the cable C1 is connected to an amplifier AP1. The amplifier AP1 amplifies the measurement signals from the accelerometers 12 to 14 and inputs the amplified signals to the management device 20. The management device 20 is a computer system that executes a process for supporting the determination of the slime settling state. The management device 20 includes a control unit 21 and a measurement information storage unit 22.

[0020] The control unit 21 executes a process for recording the slime settling state based on the measurement signal from the sensor device 10. The control unit 21 performs the processes described below (processes including an acquisition stage, an analysis stage, a determination stage, etc.). By executing a slime determination program for this purpose, the control unit 21 functions as an acquisition unit 211, an analysis unit 212, a determination unit 213, etc.

[0021] The acquisition unit 211 acquires the measurement signals of the accelerometers 12 to 14 from the amplifier AP1. The analysis unit 212 analyzes the amplified measurement signal, and calculates the frequency characteristics of the acceleration for each axis.

[0022] The determination unit 213 determines the settling state (presence or absence) of slime. The measurement information storage unit 22 stores a measurement management record of the slime settling status of each pile hole. This measurement management record is registered when an analysis process is performed. The measurement management record includes information on the site ID, pile number, work date and time, excavation depth, measurement signals of each axis, frequency characteristics of each axis, analysis results, and judgment results.

[0023] The site ID data area stores data on an identifier for identifying the site where the stake hole was formed. In the pile number data area, data on the identifier (pile number) for identifying each pile hole at this site is recorded.

[0024] The operation date and time data area records data relating to the date and time when the determination process was performed. In the excavation depth data area, data relating to the depth of the pile hole is recorded.

[0025] The measurement signal data area for each axis records data relating to the measurement signal for each axis acquired from the accelerometers 12 to 14. Here, the measurement signal records acceleration (gal) for each axis with respect to time (sec).

[0026] The frequency characteristic data area for each axis records data related to the results of frequency analysis of the measurement signal for each axis. Here, the frequency characteristic is recorded as acceleration (gal) for each axis against frequency (Hz).

[0027] The analysis result data area records data on the statistical values ​​(average value, standard deviation) of the predominant frequency of acceleration for each axis. The determination result data area records the determination result of whether or not slime is present.

[0028] (Slime determination process) The slime determination process will be described with reference to Fig. 4. In this case, the measurement information storage unit 22 is registered with a measurement management record that records the site ID of the site where the settling state of slime is to be determined, the pile number of the pile hole, and the work date and time when the work will start.

[0029] First, measurement is performed (step S11). Specifically, the worker drops a measurement tape M1 with a weight W1 attached to the tip into the pile hole H1. When the weight W1 reaches the hole bottom H2, the worker measures the excavation depth using the scale on the measurement tape M1. Then, the worker records the excavation depth in the measurement management record of the measurement information storage unit 22 using the input device H12 of the management device 20.

[0030] Next, a weight striking operation process is performed (step S12). Specifically, the worker attaches the sensor device 10 to the hand (directly below the grip position) of the measurement tape M1. Then, the measurement tape M1 is lowered from just before the hole bottom H2 so that the weight W1 strikes the hole bottom H2, and then pulled up after striking (striking operation). This causes vibrations in the measurement tape. In this embodiment, the striking operation is performed multiple times (for example, three times).

[0031] In this case, the management device 20 executes a measurement process (step S13). Specifically, when the sensor device 10 measures vibration based on acceleration, it outputs a measurement signal for the acceleration during vibration. Here, the accelerometers 12 to 14 output the measurement signal to the amplifier AP1 via the cable C1. The amplifier AP1 amplifies the measurement signal from the accelerometers 12 to 14. Then, the acquisition unit 211 of the control unit 21 of the management device 20 acquires the amplified measurement signals for acceleration for the X-axis, Y-axis, and Z-axis.

[0032] Next, the management device 20 executes an analysis process (step S14). Specifically, the analysis unit 212 of the control unit 21 of the management device 20 performs frequency analysis of the acquired amplified measurement signal for the X-axis, Y-axis, and Z-axis. Details will be described later.

[0033] Next, the management device 20 executes a recording process (step S15). Specifically, the determination unit 213 of the control unit 21 of the management device 20 records the measurement signal of each axis and the frequency characteristic of each axis in the measurement management record of the measurement information storage unit 22.

[0034] Next, the management device 20 executes a determination process (step S16). Here, the determination unit 213 outputs the frequency characteristics to the display device H13. In this case, the person in charge checks the frequency characteristics output to the display device H13.

[0035] If it is determined in the determination process (step S16) that slime has settled, slime processing is performed (step S17). Specifically, for example, a bottom-scooping bucket method is used, in which a bucket is used to scoop up the settled slime. Alternatively, an air lift method, a submersible pump method, or a suction pump method may be used. In the air lift method, compressed air is blown into the tremie pipe to create an upward water current in the pipe, which sucks up the slime along with the muddy water. In the submersible pump method, a submersible pump is used to suck up the slime. In the suction pump method, the tremie pipe is connected to a suction pump, which sucks up and discharges the slime. Then, the determination process is performed again to determine the settling status of the slime.

[0036] Then, in the determination process (step S16), if it is determined that the slime has not settled, the slime determination process is ended. After that, a concrete pile is constructed in this pile hole H1.

[0037] (Analysis processing) In this embodiment, analysis processing is performed before and after slime processing. Here, the measurement tape M1 uses acceleration in the direction perpendicular to the surface (X-axis direction), but acceleration in other axial directions may also be used.

[0038] (Analysis process before slime processing) Next, the analysis process before the slime treatment will be described with reference to FIG. 5(a). First, the control unit 21 of the management device 20 executes a process for identifying the peak position (step S21). Specifically, the analysis unit 212 of the control unit 21 identifies the peak position in the waveform of the measurement signal before slime processing recorded in the measurement information storage unit 22. Here, the peak position is identified as the time when the acceleration exceeds a predetermined value. This eliminates the influence of the preparation stage before dropping the weight W1 and hand shaking after dropping it, and identifies the time when the weight hits the bottom of the hole.

[0039] As shown in Fig. 6(a), a graph 500 before the slime processing is obtained. In this graph 500, peaks are displayed as negative values. Therefore, in the graph 500, peaks P1, P2, and P3 are identified as minimum values ​​equal to or less than the acceleration AC1.

[0040] Next, the control unit 21 of the management device 20 executes a process for identifying a peak range (step S22). Specifically, the analysis unit 212 of the control unit 21 identifies, as the peak range, the time period before and after the peak position in the detected waveform, surrounded by two intersection positions that are reference values, with the peak position in between. Here, the peak range is determined to be the range from the intersection position where the acceleration is "almost 0" to the peak position before the peak position (time t1), and from the peak position to the intersection position where the acceleration is "almost 0" to the reference value after the peak position (time t2).

[0041] As shown in FIG. 6(b), in a graph 510 before slime processing, the peak range is identified by identifying times t1 and t2 for a peak position 511. Then, the control unit 21 of the management device 20 repeats the following process for each peak.

[0042] Here, the control unit 21 of the management device 20 executes a peak range extraction process (step S23). Specifically, the analysis unit 212 of the control unit 21 identifies the waveform (detected waveform) in the peak range using times t1 and t2 for the peak position. Here, the detected waveform at time t1 before the peak position time and time t2 after the peak position time are extracted.

[0043] Graph 520 in FIG. 6(c) shows peak ranges D1, D2, and D3 corresponding to peaks P1, P2, and P3. A graph 530 in FIG. 7(a) shows the detected waveforms in the peak ranges D1, D2, and D3 on the same time axis.

[0044] Next, the control unit 21 of the management device 20 executes a frequency analysis process (step S24). Specifically, the analysis unit 212 of the control unit 21 performs a frequency analysis of the detected waveform in the peak range for the peak position.

[0045] Graph 540 in Figure 7(b) shows the results of frequency analysis of the peak range. Graph 540 shows the first dominant frequency (solid arrow) and the second dominant frequency (dashed arrow). Here, the first dominant frequencies are concentrated in the 4 to 5 Hz range.

[0046] Then, the control unit 21 of the management device 20 repeats the above process for all peaks. Next, the control unit 21 of the management device 20 executes statistical processing of the predominant frequency (step S25). Specifically, the determination unit 213 of the control unit 21 identifies the predominant frequency in the frequency analysis result of each peak, and calculates statistical values ​​(average value, standard deviation) of this predominant frequency. Here, the average value is used as an index indicating the predominant frequency, and the standard deviation is used as an index indicating the dispersion of the predominant frequency. Then, the determination unit 213 records the calculated statistical values ​​(average value, standard deviation) of the predominant frequency in the measurement information storage unit 22.

[0047] (Analysis after slime processing) Next, the analysis process after slime treatment will be described with reference to FIG. 5(b). Here, the control unit 21 of the management device 20 executes the peak position identification process in the same manner as in step S21 (step S31).

[0048] Then, the control unit 21 of the management device 20 repeats the following process for each peak. Here, the control unit 21 of the management device 20 executes a peak range extraction process (step S32). Specifically, the analysis unit 212 of the control unit 21 extracts a peak range in the waveform after the slime processing. In this case, the times t1 and t2 identified before the slime processing are used.

[0049] As shown in FIG. 8(a), in the graph 600 after slime processing, the peak range is identified by times t1 and t2 relative to the peak position. Graph 610 in FIG. 8(b) shows the detected waveforms in the three peak ranges on the same time axis.

[0050] Next, the control unit 21 of the management device 20 executes a frequency analysis process similar to step S24 (step S33). Then, the control unit 21 of the management device 20 repeats the above process for all peaks.

[0051] Next, the control unit 21 of the management device 20 performs statistical processing of the predominant frequencies in the same manner as in step S25 (step S34). Graph 620 in Fig. 8(c) shows the results of frequency analysis of the peak range. Graph 620 also shows the first dominant frequency (solid arrow) and the second dominant frequency (dashed arrow). The first dominant frequency is distributed between 15 and 21 Hz.

[0052] Next, the control unit 21 of the management device 20 executes a comparison process between the values ​​before and after the slime treatment (step S35). Specifically, the determination unit 213 of the control unit 21 outputs a confirmation screen showing the statistical value of the predominant frequency before the slime treatment and the statistical value of the predominant frequency after the slime treatment to the display device H13. In this case, the manager compares the statistical values ​​of the predominant frequency before and after the slime treatment to confirm the slime removal.

[0053] 9, a confirmation screen 700 is output on the display device H13. This confirmation screen 700 includes a pile number field 710, a measurement position field 720, vibration display fields 731 and 732, analysis result fields 741 and 742, and predominant frequency fields 751 and 752. The vibration display fields 731 and 732, analysis result fields 741 and 742, and predominant frequency fields 751 and 752 (statistical processing results) respectively output the analysis results before and after slime processing.

[0054] [Table 1] As shown in Table 1, the average value of the dominant frequency after slime treatment is larger than before slime treatment, and the standard deviation is also larger. This makes it possible to determine whether slime has been removed.

[0055] (Action of this embodiment) If slime has accumulated, the accumulated slime acts as a cushion before slime treatment. When the slime is removed, the hard hole bottom is exposed, which increases the vibration frequency during striking. Furthermore, after slime treatment, the unevenness of the hole bottom, the drop height, and changes in condition due to multiple strikes all affect the vibration, resulting in greater variation in the dominant frequency.

[0056] (Effects of this embodiment) (1) In this embodiment, the sensor device 10 is attached to the handle (directly below the grip position) of the measurement tape M1. Since the sensor device 10 is attached to the existing measurement tape M1, the worker's work can be reduced.

[0057] (2) In this embodiment, the management device 20 executes a measurement process (step S13), thereby detecting the vibration caused by the impact of the weight W1 on the tip of the measurement tape M1 based on the acceleration.

[0058] (3) In this embodiment, the management device 20 executes an analysis process (step S14). The impacting state of the weight W1 changes depending on whether or not there is slime settling at the hole bottom H2. The presence or absence of slime settling can be determined based on this impacting state.

[0059] (4) In this embodiment, the acceleration of the measurement tape M1 in the horizontal direction (the direction perpendicular to the surface, the width direction) is detected. When the weight W1 strikes the hole bottom H2, the measurement tape M1 sags. This sagging condition can be used to determine the striking condition. In particular, the measurement tape M1 sags significantly in the direction perpendicular to the surface (the X-axis direction), and the striking condition can be efficiently determined in the X-axis direction.

[0060] (4) In this embodiment, the management device 20 executes a recording process (step S15), which allows evidence of the slime settling state to be left behind. (5) In this embodiment, the control unit 21 of the management device 20 executes a process for identifying the peak position (steps S21 and S31), thereby making it possible to identify the timing at which the weight W1 strikes the hole bottom H2.

[0061] (6) In this embodiment, the control unit 21 of the management device 20 executes a peak range identification process (step S22). This makes it possible to identify the range (peak range) affected by the slime due to the impact of the weight W1. Then, in the analysis process after the slime treatment, the control unit 21 of the management device 20 also executes a peak range extraction process (step S32). This makes it possible to compare the frequency analysis results for the same time range before and after the slime treatment.

[0062] (7) In this embodiment, the control unit 21 of the management device 20 executes a peak range extraction process (steps S23 and S32), thereby extracting the detected waveform that is affected by slime due to the impact of the weight W1.

[0063] (8) In this embodiment, the control unit 21 of the management device 20 executes a frequency analysis process (steps S24 and S33), thereby analyzing the detected waveform by the dominant frequency. (9) In this embodiment, the control unit 21 of the management device 20 performs statistical processing of the dominant frequency (steps S25 and S34). This makes it possible to analyze the influence of slime by hitting the object multiple times.

[0064] (10) In this embodiment, the control unit 21 of the management device 20 executes a comparison process before and after slime treatment (step S35). This allows the change in the detected waveform due to the presence or absence of slime to be analyzed using statistical values ​​of the dominant frequency before and after slime treatment. Then, the effectiveness of the slime treatment can be determined.

[0065] This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility. In the above embodiment, the slime determining device A1 includes the sensor device 10, the amplifier AP1, and the management device 20. The hardware configuration is not limited to this configuration.

[0066] In the above embodiment, the sensor device 10 is attached to the measuring tape M1. The sensor device 10 may be attached to a rod-shaped member as long as it is a flexible member that can reach the hole bottom H2. In the above embodiment, an accelerometer 12 that measures acceleration in the Z-axis direction, an accelerometer 13 that measures acceleration in the Y-axis direction, and an accelerometer 14 that measures acceleration in the X-axis direction are used. The number of sensors is not limited to this. For example, acceleration in only one of the axial directions may be used.

[0067] In the above embodiment, the weight striking operation process is performed (step S12). Here, the weight striking operation process of the weight W1 may be performed by a machine instead of a worker. In the above embodiment, the control unit 21 of the management device 20 executes a process for identifying a peak range (step S22). Here, the range before and after the peak position, in which the acceleration reaches a reference value of "almost 0", is identified as the peak range. The reference value for determining the peak range is not limited to "almost 0". Before slime processing, the range in which vibrations due to impacts can be detected may be identified as the peak range. For example, the peak range may be identified based on a flat region where the change in acceleration is equal to or less than a predetermined value.

[0068] In the above embodiment, the control unit 21 of the management device 20 executes a peak range extraction process (step S32). In this case, the times t1 and t2 identified before the slime treatment are used. Here, different times t1 and t2 may be used before and after the slime treatment. Specifically, it is sufficient to identify the range in which vibrations caused by the impact of the weight W1 can be detected (the peak range affected by the slime).

[0069] In the above embodiment, the control unit 21 of the management device 20 performs statistical processing of the predominant frequency (step S25). Here, the average value is used as an index indicating the predominant frequency, and the standard deviation is used as an index indicating the dispersion of the predominant frequency. The index indicating the predominant frequency and the index indicating the dispersion of the predominant frequency are not limited to these.

[0070] In the above embodiment, the hammering is performed three times, but it is not limited to three times as long as it is performed multiple times. The hammering position may also be changed. In this case, if slime is present, the dominant frequency will be smaller and the variation will also be smaller. On the other hand, if slime is removed, the dominant frequency will be larger and the variation depending on the location will be larger.

[0071] In the above embodiment, the control unit 21 of the management device 20 executes a comparison process between before and after slime treatment (step S35). Here, the determination unit 213 may determine whether slime has been removed. In this case, for example, if the predominant frequency after slime treatment has increased by a predetermined value or more, it may be determined that slime removal has been completed. Also, if the variation in the predominant frequency after slime treatment has increased by a predetermined value or more, it may be determined that slime removal has been completed. Also, if the average value of acceleration at the predominant frequency is equal to or greater than an average reference value, or if the standard deviation of the predominant frequency is equal to or greater than a variation reference value, it may be determined that slime removal has been completed.

[0072] In the above embodiment, the control unit 21 of the management device 20 executes statistical processing of the predominant frequency (step S25). Here, if it is determined that no slime has accumulated based on the statistical value of the predominant frequency, slime processing may be omitted. For example, if the predominant frequency exceeds a reference value, it may be determined that no slime has accumulated. Also, if the average value of acceleration at the predominant frequency is equal to or greater than the average reference value, and the standard deviation of the predominant frequency is equal to or greater than the variation reference value, it may be determined that no slime has accumulated. Here again, the determination unit 213 may determine whether slime has accumulated.

[0073] Next, the technical ideas that can be understood from the above-described embodiment and other examples will be described below. (a) A slime determination device as described in claim 2, characterized in that in a frequency analysis of the detected waveform, removal of the slime is determined based on an increase in the statistical value of the dominant frequency over multiple impacts.

[0074] (b) A slime determination device as described in (a) or (b), characterized in that in a frequency analysis of the detected waveform, the removal of the slime is determined based on an increase in the variation in the dominant frequency when struck multiple times.

[0075] (c) A slime determination device described in any one of (a) and (b), characterized in that in the detected waveform, the range surrounded by two intersection positions that are reference values, sandwiching the peak position, is identified as the peak range. [Explanation of symbols]

[0076] H1...pile hole, SL1...slime, M1...measuring tape, W1...weight, A1...slime determination device, 10...sensor device, 11...plate material, 12, 13, 14...acceleration sensors, ST1, ST2...fixing devices, AP1...amplifier, 20...management device, 21...control unit, 211...acquisition unit, 212...analysis unit, 213...determination unit, 22...measurement information storage unit.

Claims

1. A sensor device attached to a long object capable of reaching the bottom of a pile hole of a cast-in-place concrete pile, before slime treatment and after slime treatment, respectively, is attached to a long object. A measurement information storage unit that records a plurality of detected waveforms when the long object is driven into the bottom of the hole, and a control unit that analyzes the detected waveforms. The control unit Extracting a plurality of peak ranges in the detected waveforms before and after the slime treatment recorded in the measurement information storage unit, A slime determination device characterized by outputting statistical processing results of frequency analysis results of the multiple peak ranges.

2. The slime determination device according to claim 1, characterized in that the control unit calculates at least one of an index indicating a predominant frequency and an index indicating a variation in the predominant frequency as a result of the statistical processing.

3. The slime determination device according to claim 1 or 2, characterized in that the control unit determines the peak range based on a detected waveform before the slime processing.

4. A slime determination method for determining the settling state of slime at the bottom of a pile hole using a sensor device attached to a long object that can reach the bottom of a pile hole of a cast-in-place concrete pile, Before and after slime treatment, a plurality of detection waveforms are obtained when the elongated object is struck against the bottom of the hole, A plurality of peak ranges are extracted in the detected waveforms before and after the slime treatment, A slime determination method characterized by comparing the statistical processing results of the frequency analysis results of the multiple peak ranges.

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