JP2023141056A - Confirmation device for bearing stratum, confirmation system, confirmation method, and program - Google Patents

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

The present invention relates to a support layer confirmation device, confirmation system, confirmation method, and program.

When constructing cast-in-place concrete piles, the support layer is excavated using an earth drill method, etc., and the support layer confirmation during this construction process involves comparing the excavated soil collected during excavation with the results of the boring survey (soil column diagram, soil sample). is the basis. Because the excavated soil is disturbed, it is difficult to confirm the supporting layer by observing the excavated soil in ground where there is little change in the soil quality between the supporting layer and the layer above it. There are ways to check the support layer from the vibrations of the construction machine and the movement of the Kerry bar, but objective confirmation is not possible. Furthermore, a method is also known in which a support layer is confirmed from a characteristic curve showing the relationship between excavation depth and rotational torque value from excavation data (for example, see Patent Document 1).

Japanese Patent Application Publication No. 2021-085149

In the confirmation method described in Patent Document 1, it is determined that the excavation depth has reached the support layer when the rotational torque value sharply increases from the characteristic curve. However, factors other than ground resistance such as obstacles cause the rotational torque value to increase, making it impossible to accurately confirm the support layer.

The present invention has been made in view of the above points, and an object thereof is to provide a support layer confirmation device, confirmation system, confirmation method, and program that can improve the reliability of construction of cast-in-place concrete piles using the earth drill method. do.

A support layer confirmation device according to one aspect of the present invention is a support layer confirmation device for confirming whether the depth of excavation by a bucket has reached the support layer during construction using the earth drill method, and is based on excavation data during construction. a calculation unit that calculates the energy index value required for excavation for each predetermined excavation depth; a storage unit that stores the correspondence between the energy index value and the N value obtained from the excavation data during the previous construction; and an output unit that outputs the energy index value at the time of the current construction in a manner that can be compared with the N value.

The support layer confirmation device of one aspect of the present invention outputs the energy index value obtained from the excavation data during the current construction in a manner that can be compared with the N value, so it is possible to determine whether the excavation depth has reached the support layer. It is possible to check with accuracy. The reliability of construction of cast-in-place concrete piles using the earth drill method can be improved. In addition, the stratigraphy of the ground can be understood from changes in energy index values with changes in excavation depth.

FIG. 1 is a schematic diagram of a support layer confirmation system according to the present embodiment. FIG. 2 is a functional block diagram of a support layer confirmation device according to the present embodiment. It is a figure showing the relationship between construction time and bucket depth of this embodiment. It is an enlarged view showing the relationship between the construction time and the depth of the bucket in this embodiment. It is a figure showing the relationship between rotational energy and depth of this embodiment. It is a figure showing the relationship between pseudo N value and depth of this embodiment. It is a pile-up diagram of this embodiment. FIG. 2 is a flow diagram showing a method for confirming a support layer according to the present embodiment. It is a figure which shows the relationship between the integrated rotational torque and depth of a modification. It is a figure which shows the relationship between the pseudo N value and depth of a modification.

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 in this embodiment. FIG. 4 is an enlarged view showing the relationship between construction time and bucket depth in this embodiment. FIG. 5 is a diagram showing the relationship between rotational energy and depth in this embodiment. FIG. 6 is a diagram showing the relationship between the pseudo N value and depth in this embodiment.

As shown in FIG. 1, the support layer confirmation system is mounted on an earth drilling machine 1. The earth drill machine 1 is a working machine that excavates the ground by rotating a bucket 7 attached to the lower end of a Kelly bar 6, and pulls up the excavated soil taken into the bucket 7 and discharges it to the ground. A crawler-type traveling body 2 is provided at the bottom of the earth drilling machine 1, and the crawler spanning the front and rear wheels enables the construction machine to move on uneven ground. A revolving body 3 is provided on the upper part of the traveling body 2 so as to be able to rotate in the horizontal direction, and a driver's seat 4 is formed on the front right side of the revolving body 3 and is provided with various operating levers and the like.

A boom 5 is provided on the front left side of the revolving body 3 so as to be able to rise and fall, and a Kerry bar 6 is connected to the tip of a main hoist rope hanging from a 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 on the base end side of the boom 5 via a front frame 8, and a Kelly bar 6 is inserted into the Kelly drive 9. When the Kelly bar 6 is rotated by the Kelly drive 9, the ground is excavated by the bucket 7 at the lower end of the Kelly bar 6.

The earth drill machine 1 includes an encoder 11 that detects the depth of the bucket 7, a first oil pressure sensor 12 that detects the thrust force of the Kelly bar 6, and a second oil pressure 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 the main winch, for example, and the first and second oil pressure sensors 12 and 13 and the angle sensor 14 are attached to the Kelly drive 9, for example. The angle sensor 14 uses, for example, a gear-shaped sensor disk and a proximity switch to detect the rotation angle of the bucket 7 based on a voltage change caused by a difference in distance between a tooth portion and a non-tooth portion output from the proximity switch.

Generally, in the earth drilling method, it is determined whether the excavation depth has reached the supporting layer by visually comparing the soil sample taken during the boring survey and the excavated soil taken during the excavation. However, there are limits to visually determining differences in soil quality. For this reason, a support layer confirmation device 20 is installed in the driver's seat 4 of the earth drilling machine 1 of this embodiment, and the confirmation device 20 analyzes excavation data output from each sensor 11-14. The rotational energy at the time of excavation and the N value at the time of the boring survey are displayed on the monitor 17 in a comparable manner, making it possible to accurately confirm that the depth of excavation has reached the supporting layer. Note that the N value is a test result (numeric value) for determining the strength of the ground, etc., determined by a standard penetration test.

Note that in this embodiment, the support layer confirmation device 20 is installed in the driver's seat 4, but the confirmation device 20 may be installed in another location such as an office. For example, drilling data may be sent from each sensor 11-14 of the earth drilling machine 1 to a data logger (not shown) in an office, and the drilling data stored in the data logger may be analyzed by the confirmation device 20. Further, excavation data is 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 excavating data on the memory card taken out from the portable measuring device is processed by the confirmation device 20. may be analyzed in situ.

As shown in FIG. 2, the support layer confirmation device 20 is provided with an acquisition section 21, a screening section 22, a calculation section 23, a storage section 24, and an output section 25. The acquisition unit 21 acquires excavation data at predetermined sampling intervals during construction. In this case, excavation data is output from each sensor 11-14 at an interval of 0.02 seconds, and this large amount of excavation data is sampled by the acquisition unit 21 at an interval of 0.2 seconds. By thinning out the excavation data by the acquisition unit 21, the burden of subsequent calculation processing is reduced. Note that the predetermined sampling interval can be changed as appropriate.

For example, as shown in FIG. 3, when excavation data is plotted at 0.2 second intervals in a coordinate system in which the vertical axis is depth and the horizontal axis is construction time, a plurality of mountain shapes and a plurality of valley shapes are formed. The peak part of the plot shows the excavation data acquired during the period when excavated soil was being discharged to the ground by bucket 7, and the valley bottom part of the plot shows the excavation data acquired during the period when the ground was excavated by bucket 7. It shows. In this way, when the process of discharging excavated soil excavated to a predetermined depth by the bucket 7 to the ground is one cycle, the shape of a mountain and the shape of a valley are repeated according to the excavation data acquired during one cycle.

The screening unit 22 extracts valid data from excavation data during construction. In this case, the point where the depth has become deeper than the maximum depth of one cycle before is taken as the starting point of excavation, and the point where the maximum depth is reached by the current cycle of excavation is taken as the ending point of excavation, and the excavation point obtained from the excavation start point to the excavation end point is Data becomes subject to screening. Among the data obtained from the excavation start point to the excavation end point in one cycle, data obtained while excavating to a predetermined depth from the excavation start point and data obtained while excavating to a predetermined depth to the excavation end point. Valid data is retrieved except for the data that was

For example, as shown in FIG. 4, let D be the excavation length from the excavation start point P1 to the excavation end point P2 in one cycle. Data from the excavation start point P1 to a depth of D/4 is excluded from valid data because it includes the influence of stress release caused by the excavation of the ground directly above in the excavation process one cycle before. Data from the depth of 3D/4 to the excavation end point P2 is excluded from valid data because it includes the influence of adjustment work such as leveling work. The effective excavation length for one cycle is D/2. In this way, valid data is extracted, excluding data unrelated to excavation of the earth, thereby improving the accuracy of the calculation process described later.

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

The storage unit 24 stores a conversion coefficient indicating the correspondence between the rotational energy and the N value obtained from the excavation data from the previous construction. In this case, the rotational energy required to excavate 1 m with the bucket 7 in the i-th cycle is E _TR (i), and 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). Then, a conversion coefficient α _c indicating the correspondence relationship is obtained from the following equation (2). In addition, when constructing the standard pile, the conversion coefficient α _c is calculated using the excavation data of the past project as the excavation data of the previous construction. Furthermore, instead of using the conversion coefficient α _c , the correspondence relationship may be expressed by a graph, a look-up table, or the like, in which the relationship between the rotational energy and the N value is used.

The conversion coefficient α _c may be determined for each depth range, soil type, and N value range. For example, separate conversion coefficients α _c may be obtained for depths below 15 [m] and 15 [m] or more, or separate conversion coefficients α _c may be obtained for clay soil and sandy soil. Alternatively, separate conversion coefficients α _c may be determined for N values less than 30 and for N values greater than or equal to 30. Alternatively, the average value of the separate conversion coefficients may be determined as the conversion coefficient α _c . In this embodiment, the conversion coefficient α _c is determined from the N value and rotational energy of cycles in which the N value is 30 or more. That is, in the above equation (2), the rotational energy of the i-th cycle in which the N value is 30 or more and the N value are used. This improves the conversion accuracy of the conversion coefficient α _c .

The output unit 25 outputs the rotational energy during the current construction to the monitor 17 in a manner that can be compared with the N value based on the conversion coefficient α _c . In this case, a reference scale of rotational energy according to a reference scale of N value is determined from the conversion coefficient α _c , and the rotational energy at the time of the current construction is shown in the reference scale of rotational energy. By inputting each scale of the reference scale of N values for x (N value) in the following equation (3), each scale of the reference scale of rotational energy is obtained as rotational energy E _{N =X} . By converting the standard scale of N value to the standard scale of rotational energy, it is now possible to compare the rotational energy and N value at the time of construction.

For example, as shown in FIG. 5, scale 400 [kN·m·rad/m] of the rotational energy reference scale corresponds to around scale 45 of the N value reference scale, and scale 600 [kN・m・rad/m] corresponds to around scale 65 of the standard scale of the N value. One rotational energy is calculated for each cycle during the current construction, and the rotational energy is plotted on the rotational energy standard scale. Since the rotational energy of each plot at an excavation depth of 19 m or more exceeds 500 (N value is 50), it can be confirmed that the excavation depth has reached the support layer.

Further, the estimated rotational energy corresponding to the N value of the standard penetration test result during the boring survey is determined from the conversion coefficient α _c , and the rotational energy during the current construction is outputted to the monitor 17 so that it can be compared with the estimated rotational energy. In this case, the estimated rotational energy corresponding to the N value is obtained by inputting the N value for each predetermined depth with respect to x (N value) in the above equation (3). As shown in FIG. 5, by referring to the tendency of change in estimated rotational energy with respect to change in depth, it is confirmed whether there is any abnormal tendency in change in rotational energy during the current construction. At this time, the support layer is confirmed if the rotational energy during the current construction is not significantly lower than the estimated rotational energy.

The output unit 25 may obtain a pseudo N value according to the rotational energy at the time of the current construction from the conversion coefficient α _c , and may indicate the pseudo N value on a standard scale of the N value. By inputting the rotational energy at the time of the current construction into _ETR of the following equation (4), a pseudo N value corresponding to the rotational energy at the time of the current construction is determined. For example, as shown in FIG. 6, a pseudo N value is calculated for each cycle during the current construction, and the pseudo N value is plotted on the reference scale of the N value. Since the pseudo N value of 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.

Further, the pseudo N value is outputted to the monitor 17 so that it can be compared with the N value of the standard penetration test result. As shown in Figure 6, by referring to the tendency of the change in N value in the standard penetration test results with respect to the change in depth during the boring survey, it is confirmed 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 by confirming that the pseudo N-value during the current construction is not significantly lower than the N-value during the boring survey. Note that the output unit 25 outputs at least one of an output result for confirming the support layer from the magnitude of rotational energy (see FIG. 5) and an output result for confirming the support layer from the magnitude of the pseudo N value (see FIG. 6). It suffices if it is configured to be able to output the results to the monitor 17.

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

The processing of each part of the confirmation 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, various processes are performed by the processor reading and executing programs stored in a memory. As the processor, for example, a CPU (Central Processing Unit) is used. Furthermore, the memory is constituted by one or more storage media such as ROM (Read Only Memory) and RAM (Random Access Memory) depending on the purpose.

A method for confirming the support layer will be described with reference to FIGS. 7 and 8. FIG. 7 is a pile-up diagram of this embodiment. FIG. 8 is a flowchart showing the method for confirming the support layer according to this embodiment. Note that the description will be made here using the symbols in FIGS. 1 and 2 as appropriate. In addition, an example will be described in which the N value of the boring survey result is compared with the pseudo N value according to the rotational energy at the time of current construction.

As shown in Figure 7, a plurality of piles are constructed within the site, but one of the piles must be set as the reference pile. It is preferable that a pile near the boring survey position B is set as the reference pile 19a. Since no excavation data has been detected before the construction of the first reference pile 19a, when the reference pile 19a is constructed, the arrival at the support layer is confirmed using the excavation data of past projects. When constructing the second and subsequent other piles 19b to 19d, reaching the support layer is confirmed using the excavation data detected during construction of the reference pile 19a. In addition, the soil classification obtained from the boring survey is also used as a reference to confirm that the support layer has been reached.

As shown in FIG. 8, when the construction target is the reference pile 19a (Yes in step S01), a conversion coefficient α _c obtained from excavation data of past projects is set (step S02). If the construction target is a pile 19b-19d other than the reference pile 19a (No in step S01), a conversion coefficient α _c obtained from the excavation data at the time of construction of the reference pile is set (step S03). In these cases, the conversion coefficient α _c is determined from the rotational energy calculated from the excavation data and the N value included in the boring data using the above equation (2). A correspondence relationship between the rotational energy and the N value determined from the excavation data from the previous construction is set.

Excavation data begins to be output from each sensor 11-14 to the confirmation device 20, and the earth drilling 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 every predetermined excavation depth (every cycle) from valid data (step S07). In this case, the rotational energy is calculated for each predetermined excavation depth from the rotational torque value, rotational angle, number of data in one cycle, and excavation length in one cycle included in the excavation data using the above formula (1).

Next, the output unit 25 calculates a pseudo N value from the rotational energy at each predetermined excavation depth (every cycle) (step S08). In this case, the pseudo N value is determined from the rotational energy and the conversion coefficient α _c using the above equation (4). Further, 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 in which the vertical axis is the depth and the horizontal axis is the N value (step S09). Referring to the magnitude of the pseudo N value displayed on the monitor 17, the change in the pseudo N value, and the trend of the change in the N value of the boring data (see Figure 6), the excavation depth can be adjusted to reach the supporting layer by the operator, etc. It will be checked whether you have done so.

If it is determined that the excavation depth has not reached the supporting layer, the ground is excavated again and confirmation processing is performed. When it is determined that the excavation depth has reached the support layer, the bottom of the excavation hole is expanded, etc. Note that the output unit 25 may display the rotational energy and the estimated rotational energy according to the N value on the monitor 17 in a coordinate system in which the vertical axis is the depth and the horizontal axis is the rotational energy (see FIG. 5). In addition, when the confirmation device 20 is provided with a determination section, instead of the worker determining whether the excavation depth has reached the support layer, the determination section uses the output result of the rotational energy during the current construction to determine whether the excavation depth has reached the support layer. Reaching the depth to the support layer may be determined automatically.

As described above, according to the support layer confirmation device of the present embodiment, the rotational energy obtained from the excavation data during the current construction is output in a manner that can be compared with the N value, so that the excavation depth can be adjusted to the support layer. It is possible to accurately confirm whether or not the destination has been reached. The reliability of construction of cast-in-place concrete piles using the earth drill method can be improved. It is also possible to understand the stratigraphy of the ground from changes in rotational energy with changes in excavation depth. For example, when the ground being excavated changes from clayey soil or silt to sandy soil or gravel, the rotational energy tends to increase significantly, and vice versa. Furthermore, when changing from sandy soil to gravel, the rotational energy tends to increase significantly, and vice versa. We will confirm this trend using reference piles and understand the stratigraphy based on the correspondence between the stratigraphy and the fluctuations in rotational energy. Note that since the rotational energy is used as an index, the influence of rotational stoppage of the bucket 7 due to obstacles etc. can be excluded from the output results.

Although rotational energy is used as the energy index value in the support layer confirmation device of this embodiment, 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. Hereinafter, a modification of the confirmation device using the integrated rotational torque as the energy index value will be described. In addition, in the modified example, descriptions of contents similar to those of the above embodiment will be omitted, and differences will be mainly described.

The calculation unit 23 of the modified example calculates the cumulative rotational torque required for excavation for each predetermined excavation depth from valid excavation data at the time of construction. In this case, the rotational torque value generated in the bucket 7 is T (x) [kN m], the measurement interval (0.2 seconds in this embodiment) is Δt [s], the number of data in one cycle is m, and the number of data in one cycle is m. When the excavation length is L [m], the cumulative rotational torque _STR during excavation is calculated from the following equation (5). This shows the cumulative rotational torque _STR required during excavation per 1 m, which is obtained by dividing the cumulative rotational torque value of one cycle by the excavation length of one cycle.

The storage unit 24 stores a conversion coefficient indicating the correspondence between the cumulative rotational torque and the N value obtained from the excavation data from the previous construction. In this case, the cumulative rotational torque required to excavate 1 m with the bucket 7 in the i-th cycle is S _TR (i), and 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 indicating the correspondence relationship is obtained from the following equation (6). Incidentally, when constructing the reference pile, the conversion coefficient α _c2 is calculated using the excavation data of the past project as the excavation data of the previous construction. Further, the correspondence relationship may be expressed by a graph, a look-up table, or the like, instead of the conversion coefficient α _c2 , by representing the relationship between the integrated rotational torque and the N value.

The conversion coefficient α _c2 may be determined for each depth range, soil quality, or N value range. For example, separate conversion coefficients α _c2 may be obtained for depths below 15 [m] and 15 [m] or more, or separate conversion coefficients α _c2 may be obtained for clay soil and sandy soil. Alternatively, separate conversion coefficients α _c2 may be determined for N values less than 30 and for N values greater than or equal to 30. Alternatively, the average value of the separate conversion coefficients may be determined as the conversion coefficient α _c . In the modified example, the conversion coefficient α _c2 is determined from the N value and the cumulative rotational torque of cycles in which the N value is 30 or more. That is, in the above equation (6), the integrated rotational torque of the i-th cycle in which the N value is 30 or more and the N value are used. This improves the conversion accuracy of the conversion coefficient α _c2 .

The output unit 25 outputs the integrated rotational torque during the current construction to the monitor 17 in a manner that can be compared with the N value based on the conversion coefficient α _c2 . In this case, the standard scale of the cumulative rotational torque is determined from the conversion coefficient α _c2 according to the standard scale of the N value, and the cumulative rotational torque at the time of the current construction is shown in the standard scale of the cumulative rotational torque. By inputting each scale of the standard scale of the N value for x (N value) in the following equation (7), each scale of the standard scale of the cumulative rotational torque is obtained as cumulative rotational torque S _{N =X} . By converting the standard scale of N value to the standard scale of cumulative rotational torque, it is possible to compare the cumulative rotational torque and N value during the current construction.

For example, as shown in FIG. 9, the scale 3000 [kN·m·s/m] of the reference scale of the cumulative rotational torque corresponds to the scale 30 of the standard scale of the N value, and the scale 5000 [kN·m·s/m] of the standard scale of the cumulative rotational torque corresponds to the scale 30 of the standard scale of the cumulative rotational torque. kN·m·s/m] corresponds to the scale 50 of the reference scale of the N value. One cumulative rotational torque is calculated for each cycle during the current construction, and the cumulative rotational torque is plotted on a reference scale of cumulative rotational torque. Since the cumulative rotational torque of each plot at an excavation depth of 19 m or more exceeds 5000 (N value is 50), it can be confirmed that the excavation depth has reached the support layer.

In addition, the estimated cumulative rotational torque according to the N value of the standard penetration test result during the boring survey is determined from the conversion coefficient α _c2 , and the cumulative rotational torque during the current construction is output to the monitor 17 so that it can be compared with the estimated cumulative rotational torque. be done. In this case, by inputting the N value for each predetermined depth with respect to x (N value) in the above equation (7), the estimated integrated rotational torque according to the N value is determined. As shown in FIG. 9, by referring to the tendency of the change in the estimated cumulative rotational torque with respect to the change in depth, it is confirmed whether there is any abnormal tendency in the change in the cumulative rotational torque during the current construction. At this time, the support layer is confirmed if the cumulative rotational torque during the current construction is not significantly lower than the estimated cumulative rotational torque.

The output unit 25 may obtain a pseudo N value according to the cumulative rotational torque during the current construction from the conversion coefficient α _c2 , and may indicate the pseudo N value using a reference scale of the N value. By inputting the cumulative rotational torque during the current construction into _STR of the following equation (8), a pseudo N value corresponding to the cumulative rotational torque during the current construction is obtained. For example, as shown in FIG. 10, a pseudo N value is calculated for each cycle during the current construction, and the pseudo N value is plotted on the reference scale of the N value. Since the pseudo N value of 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.

Further, the pseudo N value is outputted to the monitor 17 so that it can be compared with the N value of the standard penetration test result. As shown in Figure 10, by referring to the tendency of the N value change in the standard penetration test results with respect to the change in depth during the boring survey, it is confirmed 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 by confirming that the pseudo N-value during the current construction is not significantly lower than the N-value during the boring survey. Note that the output unit 25 outputs at least one of an output result for confirming the support layer from the magnitude of the integrated rotational torque (see FIG. 9) and an output result for confirming the support layer from the magnitude of the pseudo N value (see FIG. 10). It is sufficient that the output result can be outputted to the monitor 17.

The confirmation device 20 may be provided with a determination unit (not shown) that determines whether the excavation depth has reached the support layer based on the output result of the cumulative rotational torque during the current construction. In the case of Fig. 9, the excavation depth is determined to have reached the supporting layer when the cumulative rotational torque exceeding the threshold value (e.g., 5000 [kN・m・s/m]) continues for several cycles (e.g., 5 cycles). may be determined. Furthermore, it may be determined that the excavation depth has reached the supporting layer when the average value of the cumulative rotational torque in a predetermined section (for example, the depth range for 5 cycles or the depth range of the assumed supporting layer) exceeds a threshold value. . In the case of FIG. 10, it may be determined that the excavation depth has reached the support layer when the pseudo N value exceeding a threshold value (for example, 50) continues for several cycles (for example, 5 cycles). Furthermore, it may be determined that the excavation depth has reached the supporting layer when the average value of the pseudo N values in a predetermined section (for example, the depth range for 5 cycles or the depth range of the assumed supporting layer) exceeds a threshold value. . Thereby, it is possible to automatically determine whether the excavation depth has reached the support layer.

As described above, even in the modified support layer confirmation device, since the integrated rotational torque and the N value are outputted in a manner that can be compared, it is possible to accurately confirm whether the excavation depth has reached the support layer. The reliability of construction of cast-in-place concrete piles using the earth drill method can be improved.

In addition, in this embodiment and the modified example, the computer may function as a support layer confirmation device by installing a program on the computer. For example, by installing a program on a mobile terminal such as a tablet terminal or a smartphone, these mobile terminals may function as a confirmation device. This program may be stored in a storage medium. The storage medium is not particularly limited, but may be a non-transitory storage medium such as an optical disk, a magneto-optical disk, or a flash memory.

Further, in the present 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.

Further, in this embodiment, the rotational energy is calculated based on the above formula (1), but the method of calculating the rotational energy is not particularly limited.

Further, in this embodiment, the conversion coefficient is calculated based on the above equation (2), but the method of calculating the conversion coefficient is not particularly limited.

Further, in the modified example, the cumulative rotational torque was calculated based on the above formula (5), but the method for calculating the cumulative rotational torque is not particularly limited.

Further, in the modified example, the conversion coefficient was calculated based on the above equation (6), but the method of calculating the conversion coefficient is not particularly limited.

Further, in the present embodiment, the screening process is performed on the excavation data, but the screening process does not need to be performed on the excavation data.

As described above, the support layer confirmation device (20) of this embodiment is a support layer confirmation device for confirming whether the excavation depth by the bucket (7) has reached the support layer during construction using the earth drill method. A calculation unit (23) calculates the energy index value required for excavation at each predetermined excavation depth from the excavation data during construction, and a calculation unit (23) that calculates the correspondence between the energy index value and the N value determined from the excavation data during the previous construction. It includes a storage unit (24) for storing information, and an output unit (25) for outputting the energy index value at the time of the current construction in a manner that can be compared with the N value based on the correspondence relationship. According to this configuration, the energy index value obtained from the excavation data during the current construction is output in a manner that can be compared with the N value, so it is possible to accurately confirm whether the excavation depth has reached the supporting layer. I can do it. The reliability of construction of cast-in-place concrete piles using the earth drill method can be improved. In addition, the stratigraphy of the ground can be understood from changes in energy index values with changes in excavation depth.

In the support layer confirmation device of this embodiment, the output unit determines the standard scale of the energy index value corresponding to the standard scale of N values from the correspondence relationship, and converts the energy index value at the time of current construction into the standard scale of the energy index value. It is shown in According to this configuration, the support layer can be confirmed from the energy index value at the time of the current construction on the standard scale of the energy index value according to the standard scale of the N value.

In the support layer confirmation device of this embodiment, the output unit calculates the estimated energy index value according to the N value from the correspondence relationship, and outputs the energy index value at the time of the current construction so that it can be compared with the estimated energy index value. According to this configuration, by referring to the tendency of change in the estimated energy index value with respect to change in excavation depth, it is confirmed whether there is any abnormal tendency in the change in the energy index value during the current construction.

In the support layer confirmation device of this embodiment, the output unit calculates a pseudo N value according to the energy index value at the time of the current construction from the correspondence relationship, and indicates the pseudo N value on the standard scale of the N value. According to this configuration, the support layer can be confirmed from the pseudo N value at the time of current construction on the N value standard scale.

In the support layer confirmation 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 result. According to this configuration, it is checked whether there is any abnormal tendency in the change in the pseudo N value during the current construction by referring to the tendency of the change in the N value in the standard penetration test results with respect to the change in the excavation depth.

In the support layer confirmation device of this embodiment, the energy index value is the rotational energy required for excavation at each predetermined excavation depth. According to this configuration, since the rotational energy is used as the energy index value, it is possible to exclude from the output result the influence of the rotation of the bucket being stopped due to an obstacle or the like.

In the supporting layer confirmation device of the present 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 rotational torque value generated in the bucket by T(x). , where the rotation angle of the bucket at the measurement interval is θ(x), the number of data in one cycle is m, and the excavation length in one cycle is L, the rotational energy _ETR during excavation can be calculated from the above formula (1). It is being calculated. According to this configuration, the rotational energy during excavation per meter can be calculated.

The support layer confirmation 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 valid data, and the screening unit calculates the rotational energy required for excavation from the excavation start point to the excavation end point of the data obtained from the excavation start point to the excavation end point of one cycle. Valid data is extracted except for data obtained while excavating to a predetermined depth and data obtained while excavating to a predetermined depth to the excavation end point. According to this configuration, it is possible to accurately calculate rotational energy from valid data, excluding data unrelated to excavation of the earth.

In the support layer confirmation device of this embodiment, the rotational energy required to excavate 1 m with 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 is obtained from the above equation (2). According to this configuration, in addition to converting the N value into estimated rotational energy, it is possible to obtain a conversion coefficient for converting rotational energy into a pseudo N value.

In the support layer confirmation device of this embodiment, a conversion coefficient is obtained for each depth range, soil quality, or N value range using the N value and rotational energy. According to this configuration, conversion can be performed with high accuracy using conversion coefficients.

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

In the supporting layer confirmation device of the present 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 rotational torque value generated in the bucket by T(x). , where the measurement interval is Δt, the number of data in one cycle is m, and the excavation length in one cycle is L, the cumulative rotational torque _STR during excavation is calculated from the above equation (5). According to this configuration, the cumulative rotational torque during excavation per meter can be calculated.

The support layer confirmation device of the present 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, and the calculation unit includes The rotational energy required for excavation is calculated for each cycle from the data, and the screening unit excavates a predetermined depth from the excavation start point out of the data obtained from the excavation start point to the excavation end point of one cycle. Valid data is extracted except for data obtained during the excavation and data obtained during excavation to a predetermined depth to the excavation end point. According to this configuration, it is possible to accurately calculate the integrated rotational torque from valid data, excluding data unrelated to excavation of the earth.

In the supporting layer confirmation device of this embodiment, the cumulative rotational torque required to excavate 1 m with the bucket in the i-th cycle is S _TR (i), and the N value of the standard penetration test result corresponding to the depth of the i-th cycle is When N(i), the conversion coefficient α _c2 indicating the correspondence relationship is obtained from the above equation (6). According to this configuration, in addition to converting the N value into the estimated cumulative rotational torque, it is possible to obtain a conversion coefficient for converting the cumulative rotational torque into the pseudo N value.

In the support layer confirmation device of this embodiment, a conversion coefficient is determined for each depth range, soil quality, or N value range using the N value and the integrated rotational torque. According to this configuration, conversion can be performed with high accuracy using conversion coefficients.

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

The support layer confirmation system of this embodiment includes the support layer confirmation device described above and a sensor (11-14) that is attached to an earth drill machine and detects excavation data. Output. According to this configuration, it is possible to confirm whether the excavation depth has reached the support layer based on the excavation data output from the sensor of the earth drill machine.

The support layer confirmation method of this embodiment is a support layer confirmation method for confirming whether the excavation depth by the bucket has reached the support layer during construction using the earth drill method, and is determined from the excavation data from the previous construction. a step of setting the correspondence between the energy index value and the N value, a step of calculating the energy index value required for excavation for each predetermined excavation depth from the excavation data during the current construction, and outputting the energy index value in a manner that can be compared with the N value. According to this configuration, the reliability of construction of cast-in-place concrete piles using the earth drill method can be improved.

The program of this embodiment is a program for checking whether the depth of excavation by the bucket has reached the supporting layer during construction using the earth drill method, and is a program for checking the energy index value and N value obtained from the excavation data from the previous construction. , a step of calculating the energy index value required for excavation for each predetermined excavation depth from the excavation data during the current construction, and a step of setting the energy index value during the current construction as the N value based on the correspondence relationship. A computer is made to perform the step of outputting in a comparable manner. According to this configuration, by installing a program on the computer, the computer can be made to function as a support layer confirmation device.

Although the present embodiment and the modified example have been described, the above embodiment and the modified example may be combined in whole or in part as another embodiment.

Further, the technology of the present invention is not limited to the above-described embodiments, and may be variously changed, replaced, and transformed without departing from the spirit of the technical idea. Furthermore, if the technical idea can be realized in a different manner due to advances in technology or other derived technologies, the invention may be implemented using that method. Accordingly, the claims cover all embodiments that may fall within the scope of the technical spirit.

1: Earth drill machine 7: Bucket 11: Encoder (sensor)
12: First oil pressure sensor (sensor)
13: Second oil pressure sensor (sensor)
14: Angle sensor (sensor)
17: Monitor 20: Confirmation device 21: Acquisition unit 22: Screening unit 23: Calculation unit 24: Storage unit 25: Output unit

For example, as shown in FIG. 5, scale 400 0 [kN·m·rad/m] of the rotational energy reference scale corresponds to around scale 45 of the N value reference scale, and scale 600 0 of the rotational energy reference scale corresponds to around scale 45. [kN·m·rad/m] corresponds to around scale 65 of the standard scale of the N value. One rotational energy is calculated for each cycle during the current construction, and the rotational energy is plotted on the rotational energy standard scale. Since the rotational energy of each plot at an excavation depth of 19 m or more exceeds 5000 (N value is 50), it can be confirmed that the excavation depth has reached the supporting layer.

The confirmation device 20 may be provided with a determination unit (not shown) that determines whether the excavation depth has reached the support layer based on the output result of rotational energy during the current construction. In the case of Figure 5, if the rotational energy exceeding the threshold value (e.g. 5000 [kN・m・rad/m]) continues for several cycles (e.g. 5 cycles), the excavation depth will reach the supporting layer. may be determined. Alternatively, it may be determined that the excavation depth has reached the support layer when the average value of rotational energy in a predetermined section (for example, the depth range for 5 cycles or the assumed depth range of the support layer) exceeds a threshold value. In the case of FIG. 6, it may be determined that the excavation depth has reached the support layer when the pseudo N value exceeding the threshold value (for example, 50) continues for several cycles (for example, 5 cycles). Furthermore, it may be determined that the excavation depth has reached the supporting layer when the average value of the pseudo N values in a predetermined section (for example, the depth range for 5 cycles or the depth range of the assumed supporting layer) exceeds a threshold value. . Thereby, it is possible to automatically determine whether the excavation depth has reached the support layer.

Claims (19)

A supporting layer confirmation device for confirming whether the depth of excavation by a bucket has reached the supporting layer during construction using the earth drill method,
a calculation unit that calculates an energy index value required for excavation for each predetermined excavation depth from excavation data during construction;
a storage unit that stores the correspondence between the energy index value and the N value obtained from the excavation data during the previous construction;
A support layer confirmation device comprising: an output unit that outputs the energy index value at the time of current construction in a manner that can be compared with the N value based on the correspondence relationship. The output unit is characterized in that it obtains a standard scale of energy index values corresponding to the standard scale of N values from the correspondence relationship, and indicates the energy index value at the time of the current construction using the standard scale of energy index values. The support layer confirmation device according to claim 1. 3. The output unit calculates an estimated energy index value according to the N value from the correspondence relationship, and outputs the energy index value at the time of the current construction so that it can be compared with the estimated energy index value. Support layer confirmation device. The output unit calculates a pseudo N value according to the energy index value at the time of current construction from the correspondence relationship, and indicates the pseudo N value on a reference scale of the N value. 3. The support layer confirmation device according to any one of 3. 5. The support layer confirmation 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. The support layer confirmation device according to claim 1, wherein the energy index value is rotational energy required for excavation at each predetermined excavation depth. When one cycle is a process in which the bucket excavates to a predetermined depth and discharges the excavated soil to the ground,
The calculation unit defines a rotation torque value generated in the bucket as T(x), a rotation angle at which the bucket rotates at a measurement interval as θ(x), a number of data in one cycle as m, and an excavation length in one cycle as L. 7. The support layer confirmation device according to claim 6, wherein when the rotational energy _ETR during excavation is calculated from the following equation (1).
an acquisition unit that acquires excavation data at predetermined sampling intervals during construction;
Equipped with a screening section 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 extracts data obtained during excavation to a predetermined depth from the excavation start point and excavation to a predetermined depth to the excavation end point among the data obtained from the excavation start point to the excavation end point in one cycle. 8. The support layer confirmation device according to claim 7, wherein valid data is extracted excluding data obtained during the process. When the rotational energy required to excavate 1 m with 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 above response The support layer confirmation device according to claim 7 or 8, wherein the conversion coefficient α _c indicating the relationship is obtained from the following equation (2).
10. The support layer confirmation device according to claim 9, wherein a conversion coefficient is determined for each depth range, soil type, or N value range using the N value and rotational energy. 6. The support layer confirmation device according to claim 1, wherein the energy index value is an integrated rotational torque required for excavation at each predetermined excavation depth. When one cycle is a process in which the bucket excavates to a predetermined depth and discharges the excavated soil to the ground,
The calculation unit calculates the cumulative rotational torque S during excavation, where T(x) is the rotational torque value generated in the bucket, Δt is the measurement interval, m is the number of data in one cycle, and L is the excavation length in one cycle. 12. The support layer confirmation device according to claim 11, wherein _TR is calculated from the following equation (3).
an acquisition unit that acquires excavation data at predetermined sampling intervals during construction;
Equipped with a screening section that extracts valid data from excavation data during construction,
The calculation unit calculates the cumulative rotational torque required for excavation for each cycle from valid data,
The screening unit extracts data obtained during excavation to a predetermined depth from the excavation start point and excavation to a predetermined depth to the excavation end point among the data obtained from the excavation start point to the excavation end point in one cycle. 13. The support layer confirmation device according to claim 12, wherein valid data is extracted except for data obtained during the process. When the cumulative rotational torque required to excavate 1 m with the bucket in the i-th cycle is S _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 above-mentioned 14. The support layer confirmation device according to claim 12 or 13, wherein the conversion coefficient α _c2 indicating the correspondence relationship is obtained from the following equation (4).
15. The support layer confirmation device according to claim 14, wherein a conversion coefficient is determined for each depth range, soil type, or N value range using the N value and the integrated rotational torque. The support layer according to any one of claims 1 to 15, further comprising a determination unit that determines whether the excavation depth has reached the support layer based on the output result of the energy index value during the current construction. confirmation device. The support layer confirmation device according to any one of claims 1 to 16,
A sensor that is attached to an earth drilling machine and detects drilling data,
A support layer confirmation system characterized in that the sensor outputs excavation data to the confirmation device. A support layer confirmation method for confirming whether the excavation depth by a bucket has reached the support layer during construction using the earth drill method, the method comprising:
a step of setting a correspondence between the energy index value and the N value obtained from the excavation data during the previous construction;
a step of calculating an energy index value required for excavation for each predetermined excavation depth from excavation data during the current construction;
A method for confirming a supporting layer, comprising the step of outputting the energy index value at the time of current construction in a manner that can be compared with the N value based on the correspondence relationship. A program for checking whether the depth of excavation by a bucket has reached the supporting layer during construction using the earth drill method,
a step of setting a correspondence between the energy index value and the N value obtained from the excavation data during the previous construction;
a step of calculating an energy index value required for excavation for each predetermined excavation depth from excavation data during the current construction;
A program that causes a computer to execute the step of outputting the energy index value at the time of current construction in a manner that can be compared with the N value based on the correspondence relationship.

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