Support layer verification device, verification system, verification method, and program

Abstract

To improve dependability of a cast-in-place concrete pile construction with an earth drill method.SOLUTION: A confirmation device (20) of a bearing stratum confirms arrival of the excavation depth by a bucket (7) to a bearing stratum when constructing with an earth drill method. The confirmation device comprises a calculation part (23) of calculating an energy index value required to an excavation from an excavation data in the construction every prescribed excavation depth, a storage part (24) of storing correspondence relation between the energy index value and a N value found from the excavation data when constructing at the last time, and an output part (25) of outputting with the appearance capable of comparing between the energy index value when constructing at this time and a N value on the basis of the correspondence relation.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a support layer confirmation device, confirmation system, confirmation method, and program. [Background technology]

[0002] When constructing cast-in-place concrete piles, excavation is performed down to the bearing layer using methods such as earth drilling. Confirmation of the bearing layer during this construction process is based on comparing the excavated soil collected during excavation with the results of boring surveys (soil columnar profiles and soil samples). Because the excavated soil is disturbed, it is difficult to confirm the bearing layer by observing the excavated soil in ground where there is little change in the soil quality between the bearing layer and the layer above it. While there are methods for confirming the bearing layer from the vibration of the construction machine or the movement of the kelly bar, these do not provide objective confirmation. Another method is known for confirming the bearing layer from a characteristic curve that shows the relationship between excavation depth and rotational torque value from excavation data (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-085149 Summary of the Invention [Problem to be solved by the invention]

[0004] In the verification method described in Patent Document 1, it is determined that the excavation depth has reached the supporting layer when the rotational torque value from the characteristic curve increases sharply. However, the rotational torque value can increase due to factors other than ground resistance, such as obstacles, making it impossible to accurately verify the supporting layer.

[0005] The present invention has been made in consideration of the above points, and aims to provide a supporting layer verification device, verification system, verification method, and program that can improve the reliability of construction of cast-in-place concrete piles using the earth drill method. [Means for solving the problem]

[0006] A supporting layer verification device according to one aspect of the present invention is a supporting layer verification device for verifying whether the excavation depth of a bucket reaches the supporting layer during construction using an earth drill method, and includes: a calculation unit that calculates the rotational energy required for excavation for each predetermined excavation depth from excavation data during construction; a memory unit that stores the correspondence between the rotational energy calculated from the excavation data during the previous construction and the N value; and an output unit that outputs the rotational energy during the current construction in a manner that allows comparison with the N value based on the correspondence. When the process of the bucket excavating to a predetermined depth and discharging the excavated soil to the ground is defined as one cycle, the calculation unit calculates the rotational energy E during excavation, where T(x) is the rotational torque value generated by the bucket, θ(x) is the rotational angle by which the bucket rotates at the measurement interval, m is the number of data points in one cycle, and L is the excavation length in one cycle. TR is calculated from the following equation (9), and the rotational energy required to excavate 1 m with the bucket in the i-th cycle is E TR (i) When the N value of the standard penetration test result corresponding to the depth of the i-th cycle is N(i), the conversion coefficient α c is calculated from the following equation (10), and the conversion coefficient is calculated for each depth range or N value range using the N value and rotational energy. .

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[0007] The supporting layer confirmation device of one aspect of the present invention is rotational energy Since the value is output in a manner that can be compared with the N value, it is possible to accurately check whether the excavation depth has reached the supporting layer. This improves the reliability of the construction of cast-in-place concrete piles using the earth drill method. In addition, rotational energy The stratigraphy of the ground can also be understood from changes in the ground surface. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a schematic diagram of a support layer confirmation system according to the present embodiment. [Figure 2] FIG. 2 is a functional block diagram of the support layer confirmation device of the present embodiment. [Figure 3] FIG. 10 is a diagram showing the relationship between construction time and bucket depth in this embodiment. [Figure 4] FIG. 10 is an enlarged view showing the relationship between construction time and bucket depth in this embodiment. [Figure 5] FIG. 10 is a diagram showing the relationship between rotational energy and depth in this embodiment. [Figure 6] FIG. 10 is a diagram showing the relationship between the pseudo N value and the depth in this embodiment. [Figure 7] FIG. 2 is a pile elevation view of the present embodiment. [Figure 8] FIG. 4 is a flow chart showing a method for checking a support layer according to the present embodiment. [Figure 9] FIG. 10 is a diagram showing the relationship between integrated rotational torque and depth in a modified example. [Figure 10] FIG. 10 is a diagram showing the relationship between the pseudo N value and the depth in a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] The support layer confirmation system of this embodiment will be described below. Fig. 1 is a schematic diagram of the support layer confirmation system of this embodiment. Fig. 2 is a functional block diagram of the support layer confirmation device of this embodiment. Fig. 3 is a diagram showing the relationship between construction time and bucket depth of this embodiment. Fig. 4 is an enlarged view showing the relationship between construction time and bucket depth of this embodiment. Fig. 5 is a diagram showing the relationship between rotational energy and depth of this embodiment. Fig. 6 is a diagram showing the relationship between pseudo N value and depth of this embodiment.

[0010] As shown in Figure 1, the bearing layer confirmation system is mounted on an earth drilling machine 1. The earth drilling machine 1 is a work machine that excavates the ground by rotating a bucket 7 attached to the bottom end of a kelly bar 6, and then pulls up the excavated soil collected in the bucket 7 and discharges it to the ground. A crawler-type running body 2 is attached to the bottom of the earth drilling machine 1, and the crawlers stretched between the front and rear wheels enable the construction machine to move on uneven ground. A rotating body 3 is attached to the top of the running body 2 so that it can rotate horizontally, and a driver's seat 4 equipped with various operating levers and the like is formed on the front right side of the rotating body 3.

[0011] A boom 5 is provided on the front left side of the rotating body 3 so that it can be raised and lowered, and a kelly bar 6 is connected to the tip of a main hoisting rope that hangs down from the top sheave at the tip of the boom 5. The base end of the main hoisting rope is wound around a main hoisting winch (not shown) behind the driver's seat 4, and the kelly bar 6 is raised and lowered by driving the main hoisting winch. A kelly drive 9 is supported at the base end of the boom 5 via a front frame 8, and the kelly bar 6 is inserted into the kelly drive 9. The kelly bar 6 is rotated by the kelly drive 9, causing a bucket 7 at the lower end of the kelly bar 6 to excavate the ground.

[0012] The earth drill machine 1 is provided with an encoder 11 that detects the depth of the bucket 7, a first hydraulic sensor 12 that detects the thrust force of the kelly bar 6, a second hydraulic sensor 13 that detects the rotational torque value of the kelly bar 6, and an angle sensor 14 that detects the rotation angle of the kelly bar 6. The encoder 11 is attached to, for example, the main hoisting winch, and the first and second hydraulic sensors 12 and 13 and the angle sensor 14 are attached to, for example, the kelly drive 9. The angle sensor 14 detects the rotation angle of the bucket 7 using, for example, a gear-shaped sensor disk and a proximity switch, based on a voltage change that occurs due to the difference in distance between the tooth portion and the portion other than the tooth, as output from the proximity switch.

[0013] Generally, in earth drilling, whether the excavation depth has reached the bearing layer is determined by visually comparing soil samples collected during boring surveys with excavated soil collected during excavation. However, there are limitations to visually determining differences in soil quality. For this reason, a bearing layer confirmation device 20 is installed in the driver's seat 4 of the earth drill machine 1 of this embodiment, and the confirmation device 20 analyzes the excavation data output from each sensor 11-14. The rotational energy during excavation and the N-value during boring surveys are displayed on the monitor 17 in a comparable manner, allowing for accurate confirmation that the excavation depth has reached the bearing layer. The N-value is a test result (numerical value) used to determine the strength of the ground, etc., as determined by a standard penetration test.

[0014] In this embodiment, the support layer confirmation device 20 is installed in the driver's seat 4, but the confirmation device 20 may also be installed in another location such as an office. For example, drilling data may be sent from each sensor 11-14 of the earth drill machine 1 to a data logger (not shown) in the office, and the drilling data stored in the data logger may be analyzed by the confirmation device 20. Alternatively, drilling data may be output from each sensor 11-14 of the earth drill machine 1 to a portable measuring device (not shown) in the driver's seat 4, and the drilling data on a memory card removed from the portable measuring device may be analyzed in the office by the confirmation device 20.

[0015] As shown in FIG. 2, the support layer verification device 20 includes an acquisition unit 21, a screening unit 22, a calculation unit 23, a memory unit 24, and an output unit 25. The acquisition unit 21 acquires excavation data at a predetermined sampling interval during construction. In this case, excavation data is output from each sensor 11-14 at 0.02 second intervals, and this large amount of excavation data is sampled by the acquisition unit 21 at 0.2 second intervals. The acquisition unit 21 thins out the excavation data, thereby reducing the burden on subsequent calculation processing. The predetermined sampling interval can be changed as appropriate.

[0016] For example, as shown in Figure 3, when excavation data is plotted at 0.2-second intervals on a coordinate system with depth on the vertical axis and construction time on the horizontal axis, multiple peaks and valleys are formed. The peaks of the plots represent excavation data acquired during the period when the bucket 7 is discharging excavated soil onto the ground, and the valleys of the plots represent excavation data acquired during the period when the bucket 7 is excavating the ground. In this way, when the process of the bucket 7 excavating to a predetermined depth and discharging the excavated soil onto the ground is defined as one cycle, peaks and valleys are repeatedly formed by the excavation data acquired during one cycle.

[0017] The screening unit 22 extracts valid data from the excavation data during construction. In this case, the point deeper than the maximum depth of the previous cycle is set as the excavation start point, and the point where the maximum depth is reached by the excavation of the current cycle is set as the excavation end point, and the data obtained from the excavation start point to the excavation end point is the subject of screening. Of the data obtained from the excavation start point to the excavation end point in one cycle, valid data is extracted excluding data obtained while excavating a predetermined depth from the excavation start point and data obtained while excavating a predetermined depth to the excavation end point.

[0018] For example, as shown in Figure 4, the excavation length from the excavation start point P1 to the excavation end point P2 in one cycle is D. Data from the excavation start point P1 to a depth of D / 4 is excluded from the valid data because it includes the effects of stress release caused by the excavation of the ground directly above in the excavation process of the previous cycle. Data from a depth of 3D / 4 to the excavation end point P2 is excluded from the valid data because it includes the effects of adjustment work such as leveling work. The effective excavation length in one cycle is D / 2. In this way, by excluding data unrelated to the excavation of the ground and extracting valid data, the accuracy of the calculation process described below is improved.

[0019] The calculation unit 23 calculates the rotational energy required for excavation for each predetermined excavation depth from valid data of the excavation data during construction. In this case, when the rotational torque value generated by the bucket 7 is T(x) [kN m], the rotation angle of the bucket 7 rotated at the measurement interval (0.2 seconds in this embodiment) is θ(x) [rad], the number of data in one cycle is m, and the excavation length in one cycle is L [m], the rotational energy E during excavation is calculated as follows: TR is calculated from the following formula (1). This is the rotational energy required for excavation per meter, E TR In this embodiment, since screening is performed, the above-mentioned effective excavation length D / 2 is input as the excavation length L of one cycle.

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[0020] The storage unit 24 stores a conversion coefficient indicating the correspondence between the rotational energy and the N value, which is calculated from the excavation data from the previous construction. In this case, the rotational energy required to excavate 1 m by the bucket 7 in the i-th cycle is expressed as E TR (i) When the N value of the standard penetration test result during the boring survey corresponding to the depth of the i-th cycle is N(i), the conversion coefficient α c can be calculated from the following equation (2). When constructing the reference pile, the conversion coefficient α c The correspondence is also expressed by the conversion coefficient α c Alternatively, the relationship between the rotational energy and the N value may be expressed by a graph, a look-up table, or the like.

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[0021] Conversion coefficient α c may be calculated for each depth range, soil type, and N value range. For example, different conversion coefficients α for depths less than 15 m and 15 m or more may be used. c The conversion coefficient α can be calculated separately for clayey soil and sandy soil. c may be obtained, or different conversion coefficients α for N values ​​less than 30 and 30 or more c Alternatively, the average value of the different transform coefficients may be calculated as the transform coefficient α c In this embodiment, the conversion coefficient α can be calculated from the N value of the cycle in which the N value is 30 or more and the rotational energy. c That is, in the above formula (2), the rotational energy of the i-th cycle and the N value where the N value is 30 or more are used. This results in the conversion coefficient α c The conversion accuracy is improved.

[0022] The output unit 25 outputs a conversion coefficient α c Based on this, the rotational energy at the time of the current construction is output to the monitor 17 in a manner that can be compared with the N value. In this case, the conversion coefficient α cThe standard scale of rotational energy corresponding to the standard scale of the N value is calculated from the above, and the rotational energy at the time of construction is shown on the standard scale of rotational energy. By inputting each scale of the standard scale of the N value for x (N value) in the following formula (3), the rotational energy E N=X Each scale of the standard scale of rotational energy can be calculated as follows. By converting the standard scale of the N value to the standard scale of rotational energy, it is possible to compare the rotational energy and N value at the time of construction.

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[0023] For example, as shown in Figure 5, the rotational energy standard scale scale 400 0 [kN m rad / m] corresponds to around 45 on the standard scale of the N value, and 600 on the standard scale of the rotational energy. 0 [kN·m·rad / m] corresponds to around 65 on the standard scale of the N-value. One rotational energy was calculated for each cycle during construction this time, and the rotational energy was plotted on the standard scale of rotational energy. The rotational energy of each plot at excavation depths of 19m or more was 500 0 Since the N value exceeds 50, it can be confirmed that the excavation depth has reached the supporting layer.

[0024] Also, the conversion coefficient α c The estimated rotational energy corresponding to the N-value of the standard penetration test results from the boring survey is calculated from the above, and the rotational energy during the current construction is output to monitor 17 so that it can be compared with the estimated rotational energy. In this case, the N-value is input for each specified depth for x (N-value) in equation (3) above, and the estimated rotational energy corresponding to the N-value is calculated. As shown in Figure 5, the tendency of change in estimated rotational energy with changes in depth is used as a reference to check whether there is any abnormal tendency in the change in rotational energy during the current construction. At this time, the bearing layer is confirmed if the rotational energy during the current construction is not significantly lower than the estimated rotational energy.

[0025] The output unit 25 outputs a conversion coefficient α cThe pseudo N value corresponding to the rotational energy during construction may be calculated from the following equation (4), and the pseudo N value may be expressed on the standard scale of the N value. TR By inputting the rotational energy during the current construction into the above, a pseudo-N value corresponding to the rotational energy during the current construction can be calculated. For example, as shown in Figure 6, a pseudo-N value is calculated for each cycle during the current construction, and the pseudo-N values ​​are plotted on the standard scale for N values. Since the pseudo-N value for each plot at an excavation depth of 19 m or more exceeds 50, it can be confirmed that the excavation depth has reached the supporting layer.

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[0026] The pseudo-N value is also output to monitor 17 so that it can be compared with the N value of the standard penetration test results. As shown in Figure 6, the tendency of change in the N value of the standard penetration test results relative to changes in depth during the boring survey is used as a reference to check whether there is any abnormal tendency in the change in the pseudo-N value during the current construction. At this time, the bearing layer is confirmed if the pseudo-N value during the current construction is not significantly lower than the N value during the boring survey. Note that output unit 25 only needs to be configured to be able to output to monitor 17 at least one of the output results confirming the bearing layer from the magnitude of rotational energy (see Figure 5) and the output result confirming the bearing layer from the magnitude of the pseudo-N value (see Figure 6).

[0027] The confirmation device 20 may be provided with a determination unit (not shown) that determines whether the excavation depth reaches the supporting layer based on the rotational energy output result during the current construction. In the case of FIG. 5, a threshold value (for example, 500 0It may be determined that the excavation depth has reached the bearing layer when rotational energy exceeding the rotational energy (kN·m·rad / m) continues for several cycles (e.g., five cycles). It may also be determined that the excavation depth has reached the bearing layer when the average value of the rotational energy in a predetermined section (e.g., a depth range for five cycles or an assumed depth range of the bearing layer) exceeds a threshold. In the case of FIG. 6, it may be determined that the excavation depth has reached the bearing layer when the pseudo N value exceeds a threshold (e.g., 50) continues for several cycles (e.g., five cycles). It may also be determined that the excavation depth has reached the bearing layer when the average value of the pseudo N value in a predetermined section (e.g., a depth range for five cycles or an assumed depth range of the bearing layer) exceeds a threshold. In this way, it is possible to automatically determine whether the excavation depth has reached the bearing layer.

[0028] The processing of each part of the verification device 20 may be realized by software using a processor, or may be realized by a logic circuit (hardware) formed in an integrated circuit or the like. When a processor is used, the processor reads and executes programs stored in memory to perform various processes. As the processor, for example, a CPU (Central Processing Unit) is used. Furthermore, the memory is configured with one or more storage media such as ROM (Read Only Memory) and RAM (Random Access Memory) depending on the application.

[0029] A method for checking the supporting layer will be described with reference to Figures 7 and 8. Figure 7 is a pile plan view of this embodiment. Figure 8 is a flow chart showing a method for checking the supporting layer of this embodiment. Note that the symbols in Figures 1 and 2 will be used as appropriate for the explanation. Also, an example will be described in which the N value of the boring survey results is compared with a pseudo N value corresponding to the rotational energy during construction this time.

[0030] As shown in Figure 7, multiple piles will be constructed on the site, and one of them must be set as the reference pile. It is preferable to set the pile near boring survey position B as reference pile 19a. Because no excavation data was detected before the construction of the first reference pile 19a, excavation data from previous projects is used to confirm that the bearing layer has been reached when the reference pile 19a is constructed. When the second and subsequent piles 19b-19d are constructed, excavation data detected during the construction of reference pile 19a is used to confirm that the bearing layer has been reached. Note that the soil classification obtained from the boring survey is also used as a reference when confirming that the bearing layer has been reached.

[0031] As shown in FIG. 8, when the construction target is the reference pile 19a (Yes in step S01), the conversion coefficient α c is set (step S02). When the construction target is a pile 19b-19d other than the reference pile 19a (No in step S01), the conversion coefficient α c is set (step S03). In these cases, the conversion coefficient α is calculated from the rotational energy calculated from the drilling data and the N value included in the boring data using the above formula (2). c The relationship between rotational energy and N value calculated from the excavation data from the previous construction is set.

[0032] The sensors 11-14 start outputting excavation data to the confirmation device 20, and the earth drill machine 1 starts excavating the ground (step S04). The acquisition unit 21 acquires excavation data at predetermined sampling intervals (step S05), and the screening unit 22 extracts valid data from the excavation data (step S06). The calculation unit 23 calculates the rotational energy required for excavation for each predetermined excavation depth (each cycle) from the valid data (step S07). In this case, using the above formula (1), the rotational energy is calculated for each predetermined excavation depth from the rotational torque value, rotation angle, number of data per cycle, and excavation length per cycle included in the excavation data.

[0033] Next, the output unit 25 calculates the pseudo N value from the rotational energy for each predetermined excavation depth (each cycle) (step S08). In this case, the rotational energy and the conversion coefficient α c The pseudo N value is calculated from the above equation. Furthermore, the output unit 25 outputs the pseudo N value and the N value of the boring data to the monitor 17 in a coordinate system with the vertical axis representing the depth and the horizontal axis representing the N value (step S09). With reference to the size of the pseudo N value displayed on the monitor 17, the trends of the changes in the pseudo N value and the N value of the boring data (see FIG. 6), an operator or the like can confirm whether the excavation depth has reached the supporting layer.

[0034] If it is determined that the excavation depth has not reached the bearing stratum, the ground is excavated again and a confirmation process is carried out. If it is determined that the excavation depth has reached the bearing stratum, excavation of an enlarged portion of the excavated hole is carried out. The output unit 25 may display the rotational energy and the estimated rotational energy corresponding to the N value on the monitor 17 in a coordinate system with the vertical axis representing depth and the horizontal axis representing rotational energy (see FIG. 5). If the confirmation device 20 is provided with a determination unit, the determination unit may automatically determine whether the excavation depth has reached the bearing stratum from the output result of the rotational energy during the current construction, instead of having an operator or the like determine whether the excavation depth has reached the bearing stratum.

[0035] As described above, the bearing layer confirmation device of this embodiment outputs the rotational energy calculated from the excavation data from the current construction in a manner comparable to the N value, allowing for accurate confirmation of whether the excavation depth has reached the bearing layer. This improves the reliability of cast-in-place concrete pile construction using the earth drill method. Furthermore, the stratigraphy of the ground can be determined from the change in rotational energy relative to changes in excavation depth. For example, when the excavated ground changes from clayey soil or silt to sandy soil or gravel, rotational energy tends to increase significantly, and vice versa. Furthermore, when the ground changes from sandy soil to gravel, rotational energy tends to increase significantly, and vice versa. These trends are confirmed using a reference pile, and the stratigraphy can be determined based on the correspondence between the stratigraphy and the fluctuations in rotational energy. Furthermore, because rotational energy is used as an index, the effects of the bucket 7 stopping rotation due to obstacles, etc., can be eliminated from the output results.

[0036] Although the support layer confirmation device of this embodiment uses rotational energy as the energy index value, the energy index value may be any index value that indicates the energy required for excavation at each predetermined excavation depth. For example, the support layer confirmation device may use integrated rotational torque as the energy index value. Below, a modified confirmation device that uses integrated rotational torque as the energy index value will be described. Note that in this modified example, explanations of the same content as in the above embodiment will be omitted and differences will be mainly described.

[0037] The calculation unit 23 of the modified example calculates the integrated rotational torque required for excavation for each predetermined excavation depth from valid data of the excavation data during construction. In this case, when the rotational torque value generated by the bucket 7 is T(x) [kN m], the measurement interval (0.2 seconds in this embodiment) is Δt [s], the number of data points per cycle is m, and the excavation length per cycle is L [m], the integrated rotational torque S during excavation is calculated as follows: TR is calculated from the following equation (5): This is the integrated rotational torque S required for excavation per meter, which is calculated by dividing the integrated value of the rotational torque value for one cycle by the excavation length for one cycle. TR This shows:

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[0038] The storage unit 24 stores a conversion coefficient indicating the correspondence between the integrated rotational torque calculated from the excavation data of the previous construction and the N value. In this case, the integrated rotational torque required to excavate 1 m by the bucket 7 in the i-th cycle is expressed as S TR (i) When the N value of the standard penetration test result during the boring survey corresponding to the depth of the i-th cycle is N(i), the conversion coefficient α c2 can be calculated from the following equation (6). When constructing the reference pile, the conversion coefficient α c2 The correspondence is also expressed by the conversion coefficient α c2 Alternatively, the relationship between the integrated rotational torque and the N value may be expressed by a graph, a look-up table, or the like.

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[0039] Conversion coefficient α c2 may be calculated for each depth range, soil type, or N-value range. For example, different conversion coefficients α for depths less than 15 m and 15 m or more may be used. c2 The conversion coefficient α can be calculated separately for clayey soil and sandy soil. c2 may be obtained, or different conversion coefficients α for N values ​​less than 30 and 30 or more c2 Alternatively, the average value of the different transform coefficients may be calculated as the transform coefficient α c In a modified example, a conversion coefficient α is calculated from the N value of the cycle in which the N value is 30 or more and the integrated rotational torque. c2 That is, in the above equation (6), the integrated rotational torque of the i-th cycle and the N value where the N value is 30 or more are used. As a result, the conversion coefficient α c2 The conversion accuracy is improved.

[0040] The output unit 25 outputs a conversion coefficient α c2Based on this, the integrated rotational torque at the time of the current construction is output to the monitor 17 in a manner that can be compared with the N value. In this case, the conversion coefficient α c2 The standard scale of the integrated rotational torque corresponding to the standard scale of the N value is calculated from the above, and the integrated rotational torque at the time of construction is shown on the standard scale of the integrated rotational torque. By inputting each scale of the standard scale of the N value for x (N value) in the following formula (7), the integrated rotational torque S N=X Each scale of the standard scale of the cumulative rotational torque can be calculated as follows. By converting the standard scale of the N value into the standard scale of the cumulative rotational torque, it is possible to compare the cumulative rotational torque and N value during construction this time.

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[0041] For example, as shown in Figure 9, the 3000 [kN m s / m] mark on the cumulative rotational torque standard scale corresponds to 30 on the N-value standard scale, and the 5000 [kN m s / m] mark on the cumulative rotational torque standard scale corresponds to 50 on the N-value standard scale. One cumulative rotational torque was calculated for each cycle during construction this time, and the cumulative rotational torques are plotted on the cumulative rotational torque standard scale. Because the cumulative rotational torque for each plot at excavation depths of 19 m and above exceeds 5000 (N-value of 50), it can be confirmed that the excavation depth has reached the supporting layer.

[0042] Also, the conversion coefficient α c2 The estimated integrated rotational torque corresponding to the N value of the standard penetration test results from the boring survey is calculated from the N value, and the integrated rotational torque during the current construction is output to monitor 17 so that it can be compared with the estimated integrated rotational torque. In this case, the N value is input for each specified depth for x (N value) in equation (7) above, and the estimated integrated rotational torque corresponding to the N value is calculated. As shown in Figure 9, the tendency of change in the estimated integrated rotational torque with changes in depth is used as a reference to check whether there is any abnormal trend in the change in the integrated rotational torque during the current construction. At this time, the support layer is confirmed if the integrated rotational torque during the current construction is not significantly lower than the estimated integrated rotational torque.

[0043] The output unit 25 outputs a conversion coefficient αc2 The pseudo N value corresponding to the cumulative rotational torque at the time of construction may be calculated from the following equation (8), and the pseudo N value may be expressed on the standard scale of the N value. TR By inputting the cumulative rotational torque during the current construction into the , a pseudo-N value corresponding to the cumulative rotational torque during the current construction is calculated. For example, as shown in Figure 10, a pseudo-N value is calculated for each cycle during the current construction, and the pseudo-N values ​​are plotted on the N-value reference scale. Since the pseudo-N value for each plot at an excavation depth of 19 m or more exceeds 50, it can be confirmed that the excavation depth has reached the supporting layer.

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[0044] The pseudo-N-value is also output to monitor 17 so as to be comparable with the N-value of the standard penetration test results. As shown in FIG. 10, the tendency of change in the N-value of the standard penetration test results relative to changes in depth during the boring survey is used as a reference to check whether there is any abnormal tendency in the change in the pseudo-N-value during the current construction. At this time, the support layer is confirmed if the pseudo-N-value during the current construction is not significantly lower than the N-value during the boring survey. Note that output unit 25 only needs to be configured to be able to output to monitor 17 at least one of the output results confirming the support layer from the magnitude of the integrated rotational torque (see FIG. 9) and the output result confirming the support layer from the magnitude of the pseudo-N-value (see FIG. 10).

[0045] The confirmation device 20 may be provided with a determination unit (not shown) that determines whether the excavation depth has reached the supporting layer based on the output result of the integrated rotational torque during the current construction. In the case of FIG. 9, it may be determined that the excavation depth has reached the supporting layer when the integrated rotational torque exceeds a threshold value (e.g., 5000 [kN·m·s / m]) for several consecutive cycles (e.g., five cycles). It may also be determined that the excavation depth has reached the supporting layer when the average value of the integrated rotational torque for a predetermined section (e.g., a depth range for five cycles or an assumed depth range of the supporting layer) exceeds the threshold value. In the case of FIG. 10, it may be determined that the excavation depth has reached the supporting layer when the pseudo N value exceeds a threshold value (e.g., 50) for several consecutive cycles (e.g., five cycles). It may also be determined that the excavation depth has reached the supporting layer when the average value of the pseudo N value for a predetermined section (e.g., a depth range for five cycles or an assumed depth range of the supporting layer) exceeds the threshold value. This makes it possible to automatically determine whether the excavation depth has reached the supporting layer.

[0046] As described above, the modified supporting layer confirmation device also outputs the cumulative rotational torque and N value in a manner that can be compared, making it possible to accurately confirm whether the excavation depth has reached the supporting layer, thereby improving the reliability of construction of cast-in-place concrete piles using the earth drill method.

[0047] In this embodiment and its modified examples, a program may be installed on a computer, causing the computer to function as a support layer confirmation device. For example, a program may be installed on a mobile device such as a tablet terminal or a smartphone, causing the mobile device to function as a confirmation device. The program may be stored in a storage medium. The storage medium is not particularly limited, and may be a non-transitory storage medium such as an optical disk, a magneto-optical disk, or a flash memory.

[0048] Furthermore, in this embodiment and the modified example, the support layer confirmation device and the monitor are formed separately, but the confirmation device and the monitor may be formed integrally.

[0049] In addition, in this embodiment, the rotational energy is calculated based on the above formula (1), but the method for calculating the rotational energy is not particularly limited.

[0050] In addition, in this embodiment, the conversion coefficients are calculated based on the above formula (2), but the method for calculating the conversion coefficients is not particularly limited.

[0051] Furthermore, in the modified example, the integrated rotational torque is calculated based on the above formula (5), but the method for calculating the integrated rotational torque is not particularly limited.

[0052] In the modified example, the conversion coefficients are calculated based on the above formula (6), but the method for calculating the conversion coefficients is not particularly limited.

[0053] Furthermore, in this embodiment, the screening process is performed on the excavation data, but the screening process does not have to be performed on the excavation data.

[0054] As described above, the supporting layer confirmation device (20) of this embodiment is a supporting layer confirmation device for confirming whether the excavation depth of the bucket (7) reaches the supporting layer during construction using the earth drilling method. It includes a calculation unit (23) that calculates the energy index value required for excavation for each predetermined excavation depth from the excavation data of the current construction, a memory unit (24) that stores the correspondence between the energy index value calculated from the excavation data of the previous construction and the N value, and an output unit (25) that outputs the energy index value for the current construction in a manner comparable to the N value based on the correspondence. This configuration allows the energy index value calculated from the excavation data of the current construction to be output in a manner comparable to the N value, thereby enabling accurate confirmation of whether the excavation depth has reached the supporting layer. This improves the reliability of construction of cast-in-place concrete piles using the earth drilling method. Furthermore, the stratigraphy of the ground can be determined from the change in the energy index value relative to the change in excavation depth.

[0055] In the support layer confirmation device of this embodiment, the output unit obtains a reference scale for the energy index value corresponding to the reference scale for the N value from the correspondence relationship and displays the energy index value at the time of current construction on the reference scale for the energy index value. With this configuration, the support layer can be confirmed from the energy index value at the time of current construction on the reference scale for the energy index value corresponding to the reference scale for the N value.

[0056] In the support layer verification device of this embodiment, the output unit calculates an estimated energy index value corresponding to the N value from the correspondence relationship and outputs the energy index value during the current construction so that it can be compared with the estimated energy index value. With this configuration, it is possible to check whether there is any abnormal trend in the change in the energy index value during the current construction, by referring to the trend in the change in the estimated energy index value in response to changes in excavation depth.

[0057] In the support layer confirmation device of this embodiment, the output unit calculates a pseudo N value corresponding to the energy index value at the time of current construction from the correspondence relationship and displays the pseudo N value on the reference scale of N values. With this configuration, the support layer can be confirmed from the pseudo N value at the time of current construction on the reference scale of N values.

[0058] In the supporting layer verification device of this embodiment, the output unit outputs the pseudo N-value so that it can be compared with the N-value of the standard penetration test results. With this configuration, it is possible to check whether there is any abnormal trend in the change in the pseudo N-value during the current construction by referring to the trend in the change in the N-value of the standard penetration test results with respect to changes in excavation depth.

[0059] In the support layer verification device of this embodiment, the energy index value is the rotational energy required for excavation at each predetermined excavation depth. With this configuration, since the rotational energy is used as the energy index value, the influence of the bucket stopping due to an obstacle or the like can be eliminated from the output result.

[0060] In the support layer verification device of this embodiment, when the process of the bucket excavating to a predetermined depth and discharging the excavated soil to the ground is defined as one cycle, the calculation unit calculates the rotational energy E during excavation, where T(x) is the rotational torque value generated by the bucket, θ(x) is the rotational angle of the bucket rotated at the measurement interval, m is the number of data points in one cycle, and L is the excavation length in one cycle. TR is calculated from the above formula (1). With this configuration, the rotational energy per meter during excavation can be calculated.

[0061] The support layer verification device of this embodiment includes an acquisition unit (21) that acquires excavation data at predetermined sampling intervals during construction, and a screening unit (22) that extracts valid data from the excavation data during construction. The calculation unit calculates the rotational energy required for excavation for each cycle from the valid data, and the screening unit extracts valid data from the data obtained from the excavation start point to the excavation end point in one cycle, excluding data obtained while excavating a predetermined depth from the excavation start point and data obtained while excavating a predetermined depth to the excavation end point. With this configuration, the rotational energy can be accurately calculated from the valid data, excluding data unrelated to the excavation of the natural ground.

[0062] In the supporting layer confirmation device of this embodiment, the rotational energy required to excavate 1 m by the bucket in the i-th cycle is defined as E TR (i) When the N value of the standard penetration test result corresponding to the depth of the i-th cycle is N(i), the conversion coefficient α c is calculated from the above formula (2). According to this configuration, in addition to converting from the N value to the estimated rotational energy, it is also possible to calculate a conversion coefficient for converting from the rotational energy to the pseudo N value.

[0063] In the supporting layer confirmation device of this embodiment, a conversion coefficient is calculated for each depth range, soil type, or N value range using the N value and rotational energy. With this configuration, accurate conversion can be achieved using the conversion coefficient.

[0064] In the support layer confirmation device of this embodiment, the energy index value is the integrated rotational torque required for excavation for each predetermined excavation depth. With this configuration, it is possible to confirm whether the excavation depth has reached the support layer using the integrated rotational torque.

[0065] In the support layer verification device of this embodiment, when one cycle is defined as a process in which the bucket excavates to a predetermined depth and discharges the excavated soil to the ground, the calculation unit calculates the integrated rotational torque S during excavation, where T(x) is the rotational torque value generated by the bucket, Δt is the measurement interval, m is the number of data points in one cycle, and L is the excavation length in one cycle. TR is calculated from the above formula (5). According to this configuration, the integrated rotational torque per 1 m during excavation can be calculated.

[0066] The supporting layer verification device of this embodiment includes an acquisition unit that acquires excavation data at predetermined sampling intervals during construction, and a screening unit that extracts valid data from the excavation data during construction. The calculation unit calculates the rotational energy required for excavation for each cycle from the valid data, and the screening unit extracts valid data from the data obtained from the excavation start point to the excavation end point in one cycle, excluding data obtained while excavating a predetermined depth from the excavation start point and data obtained while excavating a predetermined depth to the excavation end point. With this configuration, it is possible to accurately calculate the integrated rotational torque from the valid data, excluding data unrelated to the excavation of the natural ground.

[0067] In the supporting layer confirmation device of this embodiment, the integrated rotational torque required to excavate 1 m by the bucket in the i-th cycle is defined as S TR (i) When the N value of the standard penetration test result corresponding to the depth of the i-th cycle is N(i), the conversion coefficient α c2 is obtained from the above formula (6). According to this configuration, in addition to converting from the N value to the estimated integrated rotational torque, it is also possible to obtain a conversion coefficient for converting from the integrated rotational torque to the pseudo N value.

[0068] In the supporting layer confirmation device of this embodiment, a conversion coefficient is calculated for each depth range, soil type, or N value range using the N value and integrated rotational torque. With this configuration, accurate conversion can be achieved using the conversion coefficient.

[0069] The supporting layer confirmation device of this embodiment includes a determination unit that determines whether the excavation depth has reached the supporting layer based on the output result of the energy index value during the current construction. With this configuration, it is possible to automatically determine whether the excavation depth has reached the supporting layer based on the comparison result.

[0070] The supporting layer confirmation system of this embodiment includes the above-mentioned supporting layer confirmation device and a sensor (11-14) attached to the earth drill machine for detecting drilling data, and the sensor outputs the drilling data to the confirmation device. With this configuration, it is possible to confirm whether the drilling depth has reached the supporting layer based on the drilling data output from the sensor of the earth drill machine.

[0071] The method for checking the bearing layer of this embodiment is a method for checking whether the excavation depth of a bucket has reached the bearing layer during construction using the earth drill method, and includes the steps of: establishing a correspondence relationship between the energy index value obtained from the excavation data of the previous construction and the N value; calculating the energy index value required for excavation for each predetermined excavation depth from the excavation data of the current construction; and outputting the energy index value of the current construction in a form comparable to the N value based on the correspondence relationship. This configuration can improve the reliability of construction of cast-in-place concrete piles using the earth drill method.

[0072] The program of this embodiment is a program for confirming whether the excavation depth of a bucket has reached the supporting layer during construction using the earth drill method, and causes a computer to execute the following steps: setting a correspondence relationship between the energy index value obtained from the excavation data of the previous construction and the N value; calculating the energy index value required for excavation for each predetermined excavation depth from the excavation data of the current construction; and outputting the energy index value of the current construction in a form that can be compared with the N value based on the correspondence relationship. According to this configuration, by installing the program in a computer, the computer can function as a supporting layer confirmation device.

[0073] Although the present embodiment and modifications have been described, other embodiments may be obtained by combining the above-described embodiments and modifications in whole or in part.

[0074] Furthermore, the technology of the present invention is not limited to the above-described embodiments, and may be variously changed, substituted, or modified within the scope of the spirit of the technical idea. Furthermore, if the technical idea can be realized in a different way due to technological advances or other derived technologies, it may be implemented using that method. Therefore, the claims cover all embodiments that may fall within the scope of the technical idea. [Explanation of symbols]

[0075] 1: Earth drill machine 7: Bucket 11: Encoder (sensor) 12: First hydraulic pressure sensor (sensor) 13: Second hydraulic sensor (sensor) 14: Angle sensor (sensor) 17: Monitor 20: Verification device 21: Acquisition Department 22: Screening Department 23: Calculation section 24: Storage part 25: Output section

Claims

1. A support layer confirmation device for confirming whether the excavation depth by a bucket has reached the support layer during construction using an earth drill method, a calculation unit that calculates the rotational energy required for excavation for each predetermined excavation depth from excavation data during construction; a storage unit that stores the correspondence between rotational energy and N value calculated from excavation data from the previous construction; an output unit that outputs the rotational energy at the time of current construction based on the correspondence relationship in a manner that can be compared with the N value, When the process of the bucket excavating to a predetermined depth and discharging the excavated soil to the ground is defined as one cycle, The calculation unit calculates the rotational energy E TR during excavation from the following equation (1), where T(x) is the rotational torque value generated in the bucket, θ(x) is the rotational angle by which the bucket rotates at the measurement interval, m is the number of data points in one cycle, and L is the excavation length in one cycle: [Equation 1] When the rotational energy required to excavate 1 m by the bucket in the i-th cycle is E TR (i) and the N value of the standard penetration test result corresponding to the depth of the i-th cycle is N(i), the conversion coefficient α c indicating the correspondence relationship can be obtained from the following equation (2): [Equation 2] A support layer confirmation device characterized in that a conversion coefficient is obtained for each depth range or N value range using the N value and rotational energy.

2. The support layer confirmation device described in claim 1, characterized in that the output unit calculates a standard scale of rotational energy corresponding to the standard scale of N values ​​from the correspondence relationship and displays the rotational energy during current construction on the standard scale of rotational energy.

3. The support layer verification device described in claim 2, characterized in that the output unit calculates an estimated rotational energy corresponding to the N value from the correspondence relationship and outputs the rotational energy during current construction so that it can be compared with the estimated rotational energy.

4. A support layer confirmation device described in any one of claims 1 to 3, characterized in that the output unit calculates a pseudo-N value corresponding to the rotational energy during the current construction from the correspondence relationship and displays the pseudo-N value on a standard scale for N values.

5. The support layer verification device according to claim 4, wherein the output unit outputs the pseudo-N value so that it can be compared with the N value of the standard penetration test result.

6. an acquisition unit that acquires excavation data at predetermined sampling intervals during construction; a screening unit that extracts valid data from excavation data during construction, the calculation unit calculates the rotational energy required for excavation for each cycle from valid data, The screening unit defines the excavation length from the excavation start point to the excavation end point of one cycle as D, and extracts valid data from the data obtained from the excavation start point to the excavation end point, excluding data obtained while excavating from the excavation start point to a depth of D / 4 and data obtained while excavating from a depth of 3D / 4 to the excavation end point; A supporting layer confirmation device as described in claim 1, characterized in that the data from the start of excavation to a depth of D / 4 includes the effects of stress release caused by the excavation of the ground directly above in the excavation process one cycle before, and the data from a depth of 3D / 4 to the end of excavation includes the effects of leveling work.

7. A support layer confirmation device for confirming whether the excavation depth by a bucket has reached the support layer during construction using an earth drill method, an acquisition unit that acquires excavation data at predetermined sampling intervals during construction; a screening unit that extracts valid data from excavation data during construction; a calculation unit that calculates an integrated rotational torque required for excavation for each predetermined excavation depth from excavation data during construction; a storage unit that stores the correspondence between the integrated rotational torque and the N value calculated from the excavation data from the previous construction; an output unit that outputs the integrated rotational torque at the time of the current construction based on the correspondence relationship in a manner that can be compared with the N value, When the process of the bucket excavating to a predetermined depth and discharging the excavated soil to the ground is defined as one cycle, The calculation unit calculates an integrated rotational torque S during excavation when the rotational torque value generated by the bucket is T(x), the measurement interval is Δt, the number of data points in one cycle is m, and the excavation length in one cycle is L. ＴＲ is calculated from the following formula (3), [Equation 3] the calculation unit calculates an integrated rotational torque required for excavation for each cycle from valid data, The screening unit defines the excavation length from the excavation start point to the excavation end point of one cycle as D, and extracts valid data from the data obtained from the excavation start point to the excavation end point, excluding data obtained while excavating from the excavation start point to a depth of D / 4 and data obtained while excavating from a depth of 3D / 4 to the excavation end point; A supporting layer confirmation device characterized in that data from the start of excavation to a depth of D / 4 includes the effects of stress release caused by the excavation of the ground directly above in the excavation process one cycle before, and data from a depth of 3D / 4 to the end of excavation includes the effects of leveling work.

8. A support layer confirmation device for confirming whether the excavation depth by a bucket has reached the support layer during construction using an earth drill method, a calculation unit that calculates an integrated rotational torque required for excavation for each predetermined excavation depth from excavation data during construction; a storage unit that stores the correspondence between the integrated rotational torque and the N value calculated from the excavation data from the previous construction; an output unit that outputs the integrated rotational torque at the time of the current construction based on the correspondence relationship in a manner that can be compared with the N value, When the process of the bucket excavating to a predetermined depth and discharging the excavated soil to the ground is defined as one cycle, The calculation unit calculates an integrated rotational torque S during excavation when the rotational torque value generated by the bucket is T(x), the measurement interval is Δt, the number of data points in one cycle is m, and the excavation length in one cycle is L. ＴＲ is calculated from the following formula (4), [Equation 4] The integrated rotational torque required to excavate 1 m with the bucket in the i-th cycle is S ＴＲ (i) When the N value of the standard penetration test result corresponding to the depth of the i-th cycle is N (i), the conversion coefficient α ｃ２ is calculated from the following equation (5): [Equation 5] Using the N value and the integrated rotational torque, a conversion coefficient α is calculated for each depth range or N value range. ｃ２ A support layer confirmation device characterized by being required to:

9. A supporting layer confirmation device as described in any one of claims 1 to 6, characterized in that it is equipped with a judgment unit that judges whether the excavation depth has reached the supporting layer based on the rotational energy output result during current construction.

10. The support layer confirmation device according to claim 9, wherein the determination unit determines that the excavation depth has reached the support layer when the rotational energy or pseudo N value exceeds a threshold value for several consecutive cycles.

11. The supporting layer confirmation device described in claim 9, characterized in that the judgment unit judges that the excavation depth has reached the supporting layer when the average value of the rotational energy or the average value of the pseudo N value in a specified section exceeds a threshold value.

12. The support layer confirmation device according to any one of claims 1 to 11; a sensor attached to the earth drill machine to detect drilling data; A supporting layer verification system characterized in that the sensor outputs drilling data to the verification device.

13. A method for checking a supporting layer to confirm whether the excavation depth by a bucket reaches the supporting layer during construction using an earth drill method, A step of setting a correspondence relationship between rotational energy and N value obtained from excavation data from the previous construction; A step of calculating rotational energy required for excavation for each predetermined excavation depth from the excavation data during current construction; and outputting the rotational energy at the time of the current construction based on the correspondence relationship in a manner that can be compared with the N value, When the process of the bucket excavating to a predetermined depth and discharging the excavated soil to the ground is defined as one cycle, In the calculating step, when the rotational torque value generated in the bucket is T(x), the rotational angle by which the bucket rotates at the measurement interval is θ(x), the number of data points in one cycle is m, and the excavation length in one cycle is L, the rotational energy E TR during excavation is calculated from the following equation (6): [Equation 6] When the rotational energy required to excavate 1 m by the bucket in the i-th cycle is E TR (i) and the N value of the standard penetration test result corresponding to the depth of the i-th cycle is N(i), the conversion coefficient α c indicating the correspondence relationship can be obtained from the following equation (7): [Equation 7] A method for confirming a supporting layer, characterized in that a conversion coefficient is calculated for each depth range or N value range using the N value and rotational energy.

14. A program for confirming whether the excavation depth of a bucket reaches the supporting layer during construction using an earth drill method, A step of setting a correspondence relationship between rotational energy and N value obtained from excavation data from the previous construction; A step of calculating rotational energy required for excavation for each predetermined excavation depth from the excavation data during current construction; and outputting the rotational energy at the time of the current construction based on the correspondence relationship in a manner that can be compared with the N value, When the process of the bucket excavating to a predetermined depth and discharging the excavated soil to the ground is defined as one cycle, In the calculating step, when the rotational torque value generated in the bucket is T(x), the rotational angle by which the bucket rotates at the measurement interval is θ(x), the number of data points in one cycle is m, and the excavation length in one cycle is L, the rotational energy E TR during excavation is calculated from the following equation (8): [Equation 8] When the rotational energy required to excavate 1 m by the bucket in the i-th cycle is E TR (i) and the N value of the standard penetration test result corresponding to the depth of the i-th cycle is N(i), the conversion coefficient α c indicating the correspondence relationship can be obtained from the following equation (9): [Equation 9] A program characterized by using the N value and rotational energy to calculate a conversion coefficient for each depth range or N value range.

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