Drilling support device and drilling support method

Abstract

To provide a drilling support device for supporting the evaluation of the hardness of stratum when drilling a pile hole, and a drilling support method.SOLUTION: A management device 20 for supporting confirmation of a hard ground includes: a drilling information storage unit 22 which stores a measurement value of vibration frequency of surface vibration, in association with a measurement position of the surface vibration; and a control unit 21 connected to a display device. The control unit 21 acquires a time sequence of the measurement values at the time of drilling, calculates a robust value regarding measurement values of a plurality of continuous measurement points in time, and outputs information regarding the hardness of the stratum using the robust values.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to an excavation support device and an excavation support method that support evaluation of the hardness of a ground layer when excavating a pile hole. [Background technology]

[0002] When constructing a structure, multiple piles are driven into a hard stratum (bearing layer) to support the load of the structure through the piles. When constructing prefabricated piles using the pre-boring method, it is necessary to confirm that the borehole reaches the hard stratum that will serve as the bearing layer. For this reason, a boring survey is conducted to determine the depth of the hard ground.

[0003] For managing the bearing stratum during drilling, an integrated current value obtained by integrating the current value of the motor of the drilling equipment by the "time required to drill a predetermined section" is used. Whether or not the drilling drill has reached the bearing stratum may be determined based on the integrated current value (see, for example, Patent Documents 1 and 2). The bearing stratum reach determination device described in Patent Document 1 displays on a monitor a chart in which the integrated value of the current value corresponding to the torque of the drilling drill while drilling a pile hole is associated with the drilling depth of the drilling drill. A reference value is obtained based on the integrated value corresponding to the reference value acquisition depth. Then, whether or not the drilling drill has reached the bearing stratum is determined based on the integrated value corresponding to a depth deeper than the reference value acquisition depth.

[0004] The judgment support system described in Patent Document 2 acquires the depth, the integral current value of the auger drive source that drives the earth auger, and the integral output value of the vibration drive source that drives the vibrator, and then displays a first index, which is the integral current value for each depth, and an index based on the integral output value for each depth on a display device. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-035635 [Patent Document 2] Japanese Patent Publication No. 2022-154203 Summary of the Invention [Problem to be solved by the invention]

[0006] The integrated current values ​​described in Patent Documents 1 and 2 generally correspond to the N-value, which is an index of ground hardness. However, there are cases where the integrated current value increases regardless of the ground hardness. For example, this occurs when an excavation rig is operating but work is interrupted. In this case, there is a possibility that a layer that is not suitable as a bearing layer may be mistakenly identified as such during construction management. [Means for solving the problem]

[0007] The excavation support device for solving the above problem includes a drilling information storage unit that stores measurements made during drilling, and a control unit connected to a display device, and supports evaluation of a geological formation. The control unit acquires a time series of measurements made during drilling from the excavation information storage unit, calculates robust values ​​for the measurements made at a plurality of consecutive measurement times, and uses the robust values ​​to output information about the hardness of the geological formation to the display device. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to assist in evaluating the hardness of a geological formation. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is an explanatory diagram illustrating a schematic configuration of an excavation support system according to an embodiment. [Figure 2] FIG. 2 is an explanatory diagram of a hardware configuration of the embodiment. [Figure 3] FIG. 4 is an explanatory diagram of measurement information in the embodiment. [Figure 4] FIG. 2 is an explanatory diagram of a processing procedure according to an embodiment. [Figure 5] FIG. 2 is an explanatory diagram of a median filter according to an embodiment. [Figure 6]10A and 10B are explanatory diagrams illustrating the effect of a median filter in an embodiment, in which FIG. 10A is an explanatory diagram illustrating the excavation time required when a median filter is not used, and FIG. 10B is an explanatory diagram illustrating the excavation time required when a median filter is used. [Figure 7] 5A, 5B, and 5C are explanatory diagrams of measurement values ​​in an embodiment, in which (a) is an N value, (b) is a current value, and (c) is an integrated current value. [Figure 8] 5A and 5B are explanatory diagrams illustrating the relationship between the converted N value and the integral current value in the embodiment, where FIG. 5A illustrates a case where a median filter is not used, and FIG. 5B illustrates a case where a median filter is used. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the excavation support device and excavation support method will be described below with reference to Figures 1 to 7. In this embodiment, it is assumed that the hardness of the ground layer is evaluated by the integrated current value acquired during the excavation of a pile hole.

[0011] As shown in FIG. 1, the excavation support system A1 includes a measuring device 10 and a management device 20 (excavation support device) that are connected via a network. When drilling pile holes h0 for installing piles of a building, an excavator M0 is used as a drilling device. The excavator M0 is equipped with a base machine M1, a mast M4, and an auger machine M6. The base machine M1 is equipped with a lower traveling body including a crawler M2 and an upper rotating body M5 including an operation room M3.

[0012] The mast M4 is erected on the base machine M1. A wire for measuring depth is provided inside the mast M4. An auger machine M6 is attached to the mast M4 so that it can be raised and lowered. The auger machine M6 is equipped with a drive motor housed in a box and a drilling rod M7 that is driven and rotated by the drive motor. A drilling head M8 is attached to the tip (lower end) of the drilling rod M7. A drilling blade is provided at the tip of the drilling head M8. The raising and lowering of the drilling head M8 is controlled by an operator in the control room M3.

[0013] In addition, a drilling water supply device (not shown) that supplies drilling water to the drilling head M8 is connected to the drilling machine M0. The amount of drilling water is adjusted by the operator in the control room M3 depending on the drilling situation. The measuring device 10 includes an ammeter 11. The ammeter 11 measures the load current of the drive motor of the auger machine M6.

[0014] (Example of hardware configuration) FIG. 2 shows an example of the hardware configuration of an information processing device H10 that functions as the measuring device 10 and the management device 20.

[0015] 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 the information processing device H10 may include other hardware.

[0016] 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 from the user.

[0017] The display device H13 is a display, a touch panel, or the like that displays various information. The storage device H14 stores data and various programs for executing various functions of the measuring device 10 and the management device 20. Examples of the storage device H14 include a ROM, a RAM, and a hard disk. The processor H15 controls each process in the measuring device 10 and the management device 20 using the programs and data stored in the storage device H14.

[0018] (Configuration of management device 20) Next, each functional unit that realizes the excavation support method will be described. In this embodiment, the management device 20 realizes the excavation support method using various information acquired from the measurement device 10.

[0019] The management device 20 is a computer system used by the construction site manager to manage the excavation. As shown in FIG. 3, the management device 20 includes a control unit 21 and an excavation information storage unit 22.

[0020] The control unit 21 performs various processes (processes such as an acquisition stage and a support stage). To this end, the control unit 21 functions as an acquisition unit 211 and a support unit 212 by executing an excavation support program stored in the memory.

[0021] The acquisition unit 211 acquires measurement information from the measurement device 10 and executes a process of registering the information in the excavation information storage unit 22 . The support unit 212 analyzes the measurement information and performs processing to estimate the depth of the hard ground. The support unit 212 holds information for determining whether the bearing layer has been reached from the integrated current value.

[0022] The excavation information storage unit 22 records excavation management information including measurement information acquired from the measuring device 10. This excavation management information is recorded when it is acquired from the measuring device 10. This excavation management information records pile number, pile hole position, measurement information, management information, and bearing layer depth.

[0023] The pile number is an identifier for identifying each pile. The pile hole position is a coordinate for specifying the position of the pile at the construction site. The measurement information includes data on measurement values ​​for each construction time. The construction time is a date and time, and is recorded periodically (for example, every 1 or 2 seconds). In this embodiment, the measurement values ​​used are the excavation time (Δt) and current value. The excavation time is the time required to excavate a unit section (the reciprocal of the excavation speed). The current value is the current value that drives the auger machine M6. The management information includes data on the adjustment value and integrated current value for each construction time. The adjustment value is the time (robust value) obtained by updating the excavation time using a median filter (robust filter). The robust value refers to a value that suppresses "variation" arising from events unrelated to the actual excavation, and in this embodiment, the median is used as the robust value. The integrated current value is the value obtained by integrating the current value over the time (median) required to excavate a specified section. Note that records during the period when the excavation rod M7 is being pulled up or when the diameter is expanded to excavate the foot protection section are removed in advance. Furthermore, the integrated current value is normalized by dividing the integrated current value by the excavation cross-sectional area so that values ​​can be compared between piles with different diameters. The bearing layer depth is the depth at which the bearing layer is determined to have been reached in this pile hole h0.

[0024] (Support processing) Next, the support process will be described with reference to FIG.

[0025] First, the control unit 21 of the management device 20 executes an excavation information acquisition process (step S11). Specifically, the acquisition unit 211 of the control unit 21 acquires measurement information (current value, required excavation time, etc.) from the measurement device 10. Then, the acquisition unit 211 records excavation management information in which the measurement information is associated with the pile number in the excavation information storage unit 22.

[0026] Next, the control unit 21 of the management device 20 executes a determination process to determine whether or not there are previous or subsequent values ​​(step S12). Here, it is assumed that measurement information at measurement time (ti) has been acquired. In this case, the support unit 212 of the control unit 21 checks whether or not measurement values ​​for the required excavation time (Δt) at measurement time (ti-2), measurement time (ti-1), and measurement time (ti) have been recorded.

[0027] When three or more consecutive measurement values ​​are recorded, such as measurement time (ti-2), measurement time (ti-1), and measurement time (ti), it is determined that there are previous and subsequent values. In this case (if "YES" in step S12), the control unit 21 of the management device 20 executes a process to obtain the median value (step S13). Specifically, the support unit 212 of the control unit 21 uses a median filter to identify the median value of the measurement values ​​(excavation time required) at measurement time (ti-2), measurement time (ti-1), and measurement time (ti). As shown in FIG. 5, the median value at the measurement time (ti-1) is calculated using the excavation times at the measurement time (ti-2) and the measurement time (ti).

[0028] Next, the control unit 21 of the management device 20 executes an update process (step S14). Specifically, the support unit 212 of the control unit 21 records the identified median value as an adjustment value in the excavation information storage unit 22. Here, the support unit 212 updates the adjustment value associated with the measurement time (ti-1) using the calculated median value. On the other hand, if it is determined that there are no previous or next values ​​("NO" in step S12), the control unit 21 of the management device 20 skips the process of acquiring the median value (step S13) and executes the update process (step S14). Specifically, the support unit 212 of the control unit 21 records the acquired value (required excavation time) this time in the excavation information storage unit 22 as an adjustment value.

[0029] Next, the control unit 21 of the management device 20 executes a process for calculating a support layer determination index (step S15). Specifically, the support unit 212 of the control unit 21 calculates an integrated current value by multiplying the current value at the measurement time when the update process was performed by the adjustment value (median), and records the calculated value in the excavation information storage unit 22. Next, the support unit 212 predicts the N value from the integrated current value. If the N value exceeds the reference value, the support unit 212 determines that the support layer has been reached, and outputs the determination result to the display device H13.

[0030] Next, the control unit 21 of the management device 20 executes a process of determining whether or not the excavation is to be terminated (step S16). Specifically, the manager checks the determination result output on the display device H13 and determines whether or not the excavation is to be terminated. If the excavation is to be terminated, the manager inputs an end signal into the input device H12.

[0031] If the end input is made (if "YES" in step S16), the control unit 21 of the management device 20 records the bearing layer depth in association with the pile number, and ends the support processing. On the other hand, if the end input has not been made ("NO" in step S16), the control unit 21 of the management device 20 returns to the excavation information acquisition process (step S11).

[0032] (Action of this embodiment) The integral current value is calculated by removing the influence of artificially stopping the excavation from the excavation time required to excavate a predetermined section.

[0033] (Effects of this embodiment) (1) In this embodiment, the control unit 21 of the management device 20 executes a process for acquiring excavation information (step S11), thereby acquiring measurement information from the measurement device 10 for determining whether the bearing layer has been reached.

[0034] (2) In this embodiment, the control unit 21 of the management device 20 executes a process to obtain the median value (step S13). In actual construction, excavation may be stopped to check the construction status or change the setup, and the auger machine M6 may be allowed to idle at the same depth. Conventional methods for calculating the integrated current value do not distinguish between cases where excavation takes a long time due to hard ground and cases where excavation is stopped manually, and therefore the integrated current value may increase due to human influence. By applying a median filter, the influence of manually stopping excavation on the required excavation time can be removed. As a result, the correlation between the N value, which is an index of ground hardness, and the integrated current value is enhanced, allowing the hardness of the ground to be accurately determined.

[0035] Figure 6(a) shows the excavation time when the median filter is not used, and Figure 6(b) shows the excavation time when the median filter is used. When the median filter is not used, a sudden spike in the excavation time is observed around a depth of 22 m, but by using the median filter, the spike can be suppressed.

[0036] (3) In this embodiment, the control unit 21 of the management device 20 executes a process for calculating the bearing layer determination index (step S15). As a result, the integral current value increases as the excavation time increases (the excavation speed decreases), and it can be determined that the excavation has reached hard ground.

[0037] Figure 7(a) shows the N value, Figure 7(b) shows the current value, and Figure 7(c) shows the integrated current value. It can be seen that there is a good correlation between the N value and the integrated current value. Figure 8 shows the results of an investigation into the relationship between the converted N-value and the integrated current value for eight piles constructed at the same site. The converted N-value was calculated by extrapolating N-values ​​of 60 or more based on the penetration amount. The coefficient of determination r2 of the linear regression for data with converted N-values ​​of 10 or more was 0.69 when the median filter was not used, as shown in Figure 8(a), and 0.72 when the median filter was used, as shown in Figure 8(b). Therefore, applying the median filter strengthens the correlation between the integrated current value and the N-value, which can assist in the evaluation of the hardness of the strata.

[0038] 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, a median filter is applied to the excavation time required, but a median filter may also be applied to the integral current value.

[0039] In the above embodiment, the measuring device 10 and the management device 20 are used, but the hardware configuration is not limited to these. For example, they may be constructed as an integrated computer system.

[0040] In the above embodiment, a median filter is applied to three consecutive measurement values. The measurement values ​​to be applied are not limited to this. For example, the number of measurement values ​​to which the median filter is applied may be changed depending on the work situation. For example, the number of measurement values ​​to which the median filter is applied in subsequent excavation may be determined depending on the noise (occurrence of outliers) and edge (detection of supporting ground) conditions in the measurement values ​​in the preceding excavation. In the above embodiment, the median is used as the robust value. The robust value is not limited to the median, as long as it is a stable value that is not affected by extreme fluctuations and is a statistically calculated value that removes outliers that are extreme fluctuations. For example, the trimmed mean, Winsorized mean, etc. may also be used.

[0041] Next, the technical ideas that can be understood from the above-described embodiment and other examples will be described below. (a) The excavation support device according to claim 2, characterized in that the control unit excludes the measurement information during excavation stoppage and uses the excavation time required during excavation.

[0042] (b) The excavation support device according to claim 1 or (a), characterized in that the control unit outputs the integral current value to the display device. (c) The excavation support device according to any one of (a) and (b) above, characterized in that the control unit determines that the supporting layer has been reached when the integrated current value becomes equal to or greater than a reference value. [Explanation of symbols]

[0043] A1...drilling support system, 10...measuring device, 20...management device, 21...control unit, 211...acquisition unit, 212...support unit, 22...drilling information storage unit.

Claims

1. An excavation support device that supports evaluation of a stratum, comprising: an excavation information storage unit that stores measurement values ​​during excavation; and a control unit connected to a display device, The control unit A time series of measurement values ​​during excavation is acquired from the excavation information storage unit; calculating a robust value for the measurement values ​​at a plurality of consecutive measurement times; An excavation support device, characterized in that information regarding the hardness of the stratum is output to the display device using the robust value.

2. The control unit As the measurement values, an excavation time required for excavating a predetermined section and a current value used for excavation are acquired, calculating an integrated current value from the current value using the robust values ​​of the plurality of required excavation times; 2. The excavation support device according to claim 1, wherein an integrated current value is output as information relating to the hardness of the stratum.

3. A method for supporting evaluation of a stratum using an excavation support device including an excavation information storage unit that stores measurement values ​​during excavation and a control unit connected to a display device, comprising: The control unit A time series of measurement values ​​during excavation is acquired from the excavation information storage unit; calculating a robust value for the measurement values ​​at a plurality of consecutive measurement times; A drilling support method, characterized in that information regarding the hardness of the stratum is output to the display device using the robust value.

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