JP2019190177A - Calculation device, excavation device, calculation method, and computer program - Google Patents

Abstract

To provide a calculation device which can calculate a strength characteristic value of object soil by a value obtained by excavating the object soil with an excavation device provided with an earth auger head during excavation.SOLUTION: A calculation device is electrically connected to an excavation device capable of attaching an earth auger head having an excavation edge on an excavation end, previously stores a model indicating a relationship among strength characteristics of soil, excavation resistance of an excavation device and a penetration depth of soil, and calculates an excavation resistance of the excavation device while excavating object soil (S103); measures the penetration depth of the excavation edge while excavating the object soil into the object soil (S105); and calculates a strength characteristic value of the object soil based on the model storing the excavation resistance and the penetration depth of the excavation edge (S107 to S113).SELECTED DRAWING: Figure 7

Description

  The present disclosure relates to an arithmetic device, a drilling device, a calculation method, and a computer program.

  Pile driving work is carried out as foundation work to support structures that are heavy with respect to the strength of the ground. Pile driving work is a work to drive piles to deep and solid ground. As a result, the ground becomes a support layer and supports the structure against earthquakes and weak ground.

At the site of pile driving work, it is necessary to confirm the solid ground (support layer). The method for obtaining the soil strength characteristic value to confirm whether or not it is a support layer is generally a two-stage method comprising the following two steps.
First step: A standard penetration test is performed to obtain the characteristic values of the support layer.
Second step: Earth auger excavation for driving piles into the support layer.

  The standard penetration test is a test to measure the physical properties of soil in-situ. The number of impacts required to allow a hammer (weight) to fall freely from a specified height and allow a sampler to penetrate into the soil in a specified amount (30 cm). It is a test to measure. The number of hits is an attribute value called N value used for estimating the stability of the ground.

  Earth auger excavation is a rotary mining technique in which a special cutting edge (excavation blade) is attached to the auger tip to excavate the ground. In earth auger excavation, the ground is excavated by the tip of the excavating blade. The excavation shear is transported upward along with the rotation of the excavation blade and discharged to the ground surface.

  In the earth auger excavation, it is judged that the pile reaches the support layer. Conventionally, in order to confirm the strength of the ground, prior to the earth auger excavation, a ground survey such as a standard penetration test is performed to obtain an N value of each layer of the ground. After that, the excavation resistance is calculated from the load current value and torque value of the motor in earth auger excavation, and the excavation hole becomes a support layer based on the relationship between the ground strength calculated from the excavation resistance and the N value of each layer by the preliminary ground survey. Has been determined (Japanese Patent Laid-Open No. 2002-348868).

JP 2002-348868 A

  However, in the above conventional method, the soil strength characteristic value is calculated in both the standard penetration test and the earth auger excavation step, and the calculation of the strength characteristic value is duplicated.

  In addition, in the hard and soft ambiguous ground where the N value gradually increases, it may be difficult to determine whether the pile reaches the support layer. In addition, the accuracy of the judgment is affected by the skill difference of the operator of the excavator.

  According to one embodiment, the computing device is a computing device that is electrically connected to an excavator that can be fitted with an earth auger head having a drilling blade at the excavation end, the soil strength characteristics and the excavation resistance of the excavator. And a model indicating the relationship between the penetration depth of the soil and the depth of penetration of the excavating blade during excavation of the target soil by calculating excavation resistance of the excavator during excavation of the target soil. And the strength characteristic value of the target soil is calculated based on the excavation resistance and the penetration depth of the excavation blade and the stored model.

  According to another embodiment, the excavator includes an excavator that can be attached with an earth auger head having an excavator blade at the excavation end, and the arithmetic device electrically connected to the excavator.

  According to another embodiment, the calculation method is a calculation method of the strength characteristic value of the target soil excavated by an excavator equipped with an earth auger head, the step of calculating excavation resistance of the excavator, A step of measuring the depth of penetration of the excavation blade attached to the excavation edge into the target soil, a model showing the relationship between the strength characteristics of the soil and the excavation resistance of the excavator and the penetration depth of the soil, the excavation resistance and the excavation blade And calculating a strength characteristic value of the target soil based on the penetration depth of.

  According to another embodiment, the computer program is a program for causing a computer to calculate the strength characteristic value of the target soil excavated by an excavator equipped with an earth auger head, and the computer calculates the excavation resistance of the excavator. The step of measuring the depth of penetration of the excavating blade attached to the excavation end of the earth auger head into the target soil, and the relationship between the strength characteristics of the soil, the excavation resistance of the excavator and the depth of penetration of the soil The step of calculating the strength characteristic value of the target soil based on the model and the excavation resistance and the penetration depth of the excavation blade is executed.

FIG. 1 is a schematic diagram for explaining a configuration of an excavator according to an embodiment. FIG. 2 is a diagram illustrating an example of a configuration of an arithmetic device included in the excavator. FIG. 3 is a block diagram showing the calculation process of the intensity characteristic value executed by the control unit of the calculation device. FIG. 4 is a diagram for explaining the penetration depth of the excavating blade. FIG. 5 is a diagram for explaining the resistance applied to the head body of the excavator. FIG. 6 is a diagram showing an outline of a test for obtaining the soil removal resistance and the resistance due to the weight of the soil. FIG. 7 is a flowchart showing an example of a flow of intensity characteristic value calculation processing executed by the control unit in the embodiment. FIG. 8 is a plot of the tip rotation excavation torque value obtained by the experiments by the inventors and the value of the penetration depth of the excavation blade.

[1. Outline of Arithmetic Device, Drilling Device, Calculation Method, and Computer Program]

(1) An arithmetic device included in the present embodiment is an arithmetic device that is electrically connected to an excavator that can be attached with an earth auger head having an excavating blade at the excavation end. The model showing the relationship between the excavation resistance and the soil penetration depth is stored in advance, the excavation resistance of the excavator during excavation of the target soil is calculated, and the excavation blade penetrates into the target soil during excavation of the target soil The depth is measured, and the strength characteristic value of the target soil is calculated based on the excavation resistance and the penetration depth of the excavation blade and the stored model.

  Since the strength characteristic value of the target soil can be calculated using information obtained from the excavator during excavation of the target soil, the strength characteristic value of the target soil by excavation without performing a strength test such as a standard penetration test in advance. To reach the support ground.

(2) Preferably, the strength characteristic value includes an adhesive force and an internal friction angle. That is, the adhesive strength and the internal friction angle of the target soil can be obtained by excavation without performing a strength test such as a standard penetration test in advance. Therefore, the arrival to the supporting ground can be determined using these attributes.

(3) Preferably, the arithmetic unit represents the calculated excavation resistance by an approximate expression using the measured penetration depth of the excavating blade, and stores the approximated excavation blade penetration depth coefficient. The strength characteristic value of the target soil is calculated by comparing with the coefficient of the penetration depth of the excavation blade in the model. Thereby, the intensity | strength characteristic value of object soil can be obtained by excavation.

(4) Preferably, the computing device is used for calculating the strength characteristic value by removing the soil removal resistance and the resistance due to the dead weight of the soil on the screw of the earth auger head from the calculated excavation resistance. In (1), any of excavation resistance excluding resistance due to earth removal resistance and resistance due to the dead weight of the earth on the screw of the earth auger head, or excavation resistance not removed may be used. In the former case, the calculation accuracy of the calculated intensity characteristic value can be improved. On the other hand, in the latter case, although the calculation accuracy is not improved as much as the former, the calculation can be facilitated.

(5) The excavator included in the present embodiment includes an excavator capable of attaching an earth auger head having an excavating blade at an excavation end, and (1) to (4) electrically connected to the excavator And an arithmetic unit according to any one of the above. Since this excavator is a device on which the arithmetic devices (1) to (4) are mounted, the same effect as the arithmetic devices described in (1) to (4) can be obtained.

(6) The calculation method included in the present embodiment is a calculation method of the strength characteristic value of the target soil excavated by the excavator equipped with the earth auger head, the step of calculating the excavation resistance of the excavator, The step of measuring the penetration depth of the excavating blade attached to the excavation end of the auger head into the target soil, a model showing the relationship between the strength characteristics of the soil, the excavation resistance of the excavator and the penetration depth of the soil, and the excavation resistance And calculating a strength characteristic value of the target soil based on the penetration depth of the excavation blade. Since this calculation method is a calculation method in the arithmetic devices (1) to (4), the same effects as the arithmetic devices described in (1) to (4) are obtained.

(7) A computer program included in the present embodiment is a program for causing a computer to calculate a strength characteristic value of a target soil excavated by an excavator equipped with an earth auger head. Between the step of calculating the depth, the step of measuring the depth of penetration of the excavating blade attached to the excavation end of the earth auger head, and the strength characteristics of the soil, the excavation resistance of the excavator and the depth of penetration of the soil And a step of calculating a strength characteristic value of the target soil based on the excavation resistance and the penetration depth of the excavation blade. Since this computer program causes the computer to function as the arithmetic devices (1) to (4), the computer program has the same effects as the arithmetic devices described in (1) to (4).

[2. Examples of arithmetic device, excavator, calculation method, and computer program]

<Configuration of excavator>
FIG. 1 is a schematic diagram for explaining a configuration of an excavating apparatus 100 according to the present embodiment. Referring to FIG. 1, excavation apparatus 100 includes an excavator 3. The excavator 3 includes an operation unit (not shown).

  The earth auger head 1 can be attached to and detached from the excavator 3. The earth auger head 1 has a rotatable head body 2. The head body 2 has a fixed shaft 22, and the base end side of the fixed shaft 22 is attached to the excavator 3. The fixed shaft 22 is provided with a screw 21 that extends spirally in the axial direction. An excavation blade 23 is provided at the excavation end of the fixed shaft 22.

  The excavator 100 includes a computing device 5 that is electrically connected to the excavator 3. The arithmetic device 5 is composed of a general PC (personal computer) or the like. The excavator 3 has a drive unit 31 for driving the head body 2 to rotate. The drive unit 31 includes a motor MO. The motor MO is an electric drive motor or a hydraulic drive motor.

  The load of the motor MO during excavation is input to the arithmetic device 5. In the following example, it is assumed that the motor MO is an electric drive motor. In this case, the load of the motor MO during excavation is the value of the load current applied to the motor MO, and an electric signal (first signal) indicating the value is input to the arithmetic device 5.

  In addition, a sensor such as an encoder (not shown) that detects the amount of rotation of the fixed shaft 22 is connected to the drive unit 31. The rotation amount is a rotation distance, a rotation angle, or the like. The rotation amount of the fixed shaft 22 detected by the sensor is converted into an electric signal (second signal) and input to the arithmetic unit 5.

  The excavator 3 includes a sensor (not shown) that detects the amount of excavation. The amount of digging is, for example, the traveling distance in the axial direction of the fixed shaft 22. The amount of excavation detected by the sensor is converted into an electric signal (third signal) and input to the arithmetic unit 5.

<Calculation device>
The computing device 5 included in the excavator 100 calculates the strength characteristic value of the target soil using information obtained during excavation of the target soil by the excavator 3. The strength characteristic value is, for example, an adhesive force c and an internal friction angle φ.

  FIG. 2 is a diagram illustrating an example of the configuration of the arithmetic device 5. Referring to FIG. 2, computing device 5 includes a control unit 51. The control unit 51 includes a CPU (Central Processing Unit). The CPU of the control unit 51 includes one or a plurality of large scale integrated circuits (LSIs). In a CPU including a plurality of LSIs, the plurality of LSIs cooperate to realize the function of the CPU.

  The arithmetic device 5 includes a storage unit 52. The storage unit 52 stores an application 53 including one or more programs. The CPU of the control unit 51 can read out the application 53 stored in the storage unit 52 and execute various processes. The application 53 can be transferred while being recorded on a recording medium such as a CD-ROM or DVD-ROM, or can be transferred by downloading from a computer device such as a server computer.

  The storage unit 52 includes a flash memory, an EEPROM (Electrically Erasable Programmable Read Only Memory), or a nonvolatile memory element such as a ROM, and a volatile memory element such as a RAM (Random Access Memory). The nonvolatile memory element has a storage area for storing data necessary for executing the application or the application 53.

  The arithmetic device 5 includes an input unit 54. The input unit 54 receives information input from the excavator 3 that is excavating the target soil, and inputs the input information to the control unit 51.

  The arithmetic device 5 includes a display unit 55. The control unit 51 generates display data according to the application 53 and causes the display unit 55 to display the display data.

<Calculation of soil strength characteristic value>
FIG. 3 is a block diagram showing the calculation process of the intensity characteristic value executed by the control unit 51. Referring to FIG. 3, the calculation process includes a measurement process 511. The measurement process 511 is a process for measuring the penetration depth d of the excavating blade.

  The penetration depth d of the excavation blade is a depth at which the excavation blade penetrates the soil, and is measured, for example, as an amount of excavation per rotation of the fixed shaft 22. As an example, the control unit 51 divides the excavation amount of the excavator 3 of the fixed shaft 22 obtained from the third signal by the rotation amount of the fixed shaft 22 obtained from the second signal. The amount of digging, that is, the penetration depth d of the digging blade is measured.

  As another example, the control unit 51 monitors the rotation of the fixed shaft 22 from the second signal, and the excavator 3 advances from the third signal to the time when the fixed shaft 22 makes one rotation from the monitoring start point. The penetration depth d of the excavating blade may be measured by measuring the amount.

  FIG. 4 is a diagram for explaining the penetration depth d of the excavating blade. Referring to the figure, when excavation blade 23 rotates clockwise around the central axis O of fixed shaft 22, excavation blade 23 excavates the triangular prism soil indicated by AEFADC in the figure as a fracture portion.

  The plane ABDE is a horizontal plane, the side ED is on the surface of the screw 21, and the side FC is coincident with the tip 23a of the excavating blade 23. That is, the surface EFCD coincides with the surface of the screw 21. The penetration depth d of the excavating blade is the distance from the point C coinciding with the tip 23a of the excavating blade 23 to the side BD on the plane ABDE, that is, the length of the perpendicular dropped from the point C to the side BD in the figure. .

  When the excavating machine 3 controls the excavation speed to be constant, the penetration depth d of the excavating blade, for example, the amount of excavation per rotation of the fixed shaft 22 is calculated based on the set excavation speed. May be.

  The calculation process includes a first calculation process 512. The first calculation process 512 is a process for calculating the excavation resistance of the excavator 3. The excavation resistance is, for example, resistance (tip rotation excavation torque) M in the rotation direction of the excavation end of the fixed shaft 22. In order to calculate the tip rotation excavation torque M, the control unit 51 determines, for example, the amount of change in the current value per unit time or the current from the load current value indicated by the first signal input from the excavator 3. The amount of change per unit time of the integrated current value, which is the integrated value of the value and the excavation time, is calculated, and the rotary excavation torque M1 is calculated from the value.

The rotational excavation torque M1 calculated from the first signal corresponds to the resistance applied to the head body 2 during excavation. The resistance applied to the head main body 2 during excavation may include other resistances other than the tip rotation excavation torque M, such as friction between a surface other than the excavation end and the surrounding ground. FIG. 5 is a diagram for explaining the resistance (total resistance R) applied to the head main body 2. Referring to the drawing, the total resistance R is expressed by the following formula (1).
R = Rs + Rf + Rt Formula (1)
However, each resistance Rs, Rf, Rt is defined as follows.
Rs: resistance due to the dead weight of the soil on the screw 21 Rf: soil removal resistance Rt: tip excavation resistance

  The soil removal resistance Rf is the friction between the side surface of the screw 21 and the hole wall, indicated by the arrow a in the figure, the friction between the soil on the screw 21 and the hole wall, indicated by the arrow b, and the arrow c. It includes the friction between the upper surface of the screw 21 and the soil on the screw 21 as shown.

  Therefore, the arithmetic unit 5 calculates the tip excavation resistance Rt by subtracting the soil discharge resistance Rf and the resistance Rs due to the dead weight of the soil on the screw 21 from the total resistance R (Rt = R−) from the above equation (1). Rf−Rs), the tip rotary excavation torque M is calculated from the rotary excavation torque M1.

  The soil removal resistance Rf and the resistance Rs due to the dead weight of the soil on the screw 21 are obtained by testing as an example. FIG. 6 is a diagram showing an outline of the test for obtaining the resistance Rf and the resistance Rs, and shows the test flow in the order of (A), (B), and (C). With reference to the figure, the fixed shaft 22 is rotated to perform normal excavation (A). When the excavation is advanced to some extent, the excavation is stopped (B). In this state, the screw 21 is rotated in a state where there is no excavation soil on the excavation blade 23 provided at the excavation end of the fixed shaft 22 by continuing (rotating) the rotation without excavating (C). That is, in this state, the tip excavation resistance Rt is not applied to the head main body 2, and only the earth discharge resistance Rf and the resistance Rs due to the dead weight of the soil on the screw 21 are applied. Therefore, by measuring the resistance value in this state and subtracting the resistance value from the total resistance R during excavation, the tip excavation resistance Rt is obtained by eliminating the soil removal resistance Rf and the resistance Rs due to the dead weight of the soil on the screw 21. Can do.

  Therefore, the arithmetic unit 5 stores the resistance value obtained in the test of FIG. 6 as an example, and subtracts it from the total resistance R corresponding to the rotational excavation torque M1 calculated from the first signal, thereby rotating the tip. A drilling torque M is obtained.

The calculation process of the intensity characteristic value includes a second calculation process 513. The second calculation process 513 is a process for calculating the strength characteristic value of the target soil that is the adhesive force c and the internal friction angle φ from the calculated tip rotation excavation torque M and the measured penetration depth d of the excavation blade. It is. In the second calculation processing 513, the control unit 51 approximates the relationship between the calculated tip rotation excavation torque M and the measured penetration depth d of the excavating blade by the following equation (2).
M = f1 (c, φ) d ² + f2 (c, φ) d (2)

Further, the control unit 51 stores a formula (model) of the tip rotational excavation torque M represented by the following formula (3). The formula of the tip rotation excavation torque M is an equation represented by equation (3), which is expressed as a function of the penetration depth d of the excavating blade with the soil strength characteristic value equation as a coefficient. The formula is an expression obtained by the inventor of the present application by expanding the “theoretical formula of a three-dimensional excavation model in“ flat blade excavation ”” published by McKies and Ali in 1967.
M = D1 (c, φ) d ² + D2 (c, φ) d (3)
D1 (c, φ) = {γb / 2 · (b / 2 + b1) (cotα + cotβ)} / {cot (α + δ) + cot (β + φ)} + (b + b1) / 2 · (cotα + cotβ) · (Ko · γ · z · tanφ + c)
D2 (c, φ) = (b / 2 + b1) · b (1 + cotβcot (β + φ)) c / {cot (α + δ) + cot (β + φ)}
However, each parameter is defined as follows.
α: Angle between digging blade and ground surface (deg)
β: Angle between the fracture surface and the ground surface (deg)
φ: Internal friction angle of the soil (deg)
δ: Friction angle between soil and blade (deg)
γ: Unit volume weight of soil (kN / m ³ )
b: Shaft diameter of the auger fixed shaft (cm)
b1: Excavation blade width (cm)
d: Drilling blade penetration depth (cm)
z: Drilling depth (m)
Ko: Static earth pressure coefficient

  The controller 51 uses the above equations (2) and (3) to calculate the adhesive force c and the internal friction angle φ from the calculated tip rotation excavation torque M and the measured penetration depth d of the excavation blade. Is calculated. A specific calculation method will be described later.

  Preferably, the calculation process of the intensity characteristic value includes a display process 514. Preferably, the display process 514 is a process of displaying the adhesive force c and the internal friction angle φ obtained by the second calculation process 513 on a display device such as a display (not shown) included in the excavator 100. The display device may be mounted on the arithmetic device 5, may be mounted on the excavator 3, or may be an independent device that is electrically connected to the arithmetic device 5.

<Processing flow>
FIG. 7 is a flowchart showing an example of the flow of intensity characteristic value calculation processing executed by the control unit 51 in the present embodiment. Referring to the figure, first, control unit 51 receives an input of a signal indicating a state obtained during excavation from excavator 3 that is excavating target soil at a certain depth (referred to as a target position) (step S101). ).

  The control unit 51 calculates the amount of change in the current value per unit time from the value of the load current indicated by the first signal input in step S101, and calculates the rotational excavation torque M1 from the value. Next, the excavation is stopped at that position, and the fixed shaft 22 is rotated (i.e., rotated). From the first signal from the excavator 3 in that state, the soil removal resistance Rf and the resistance due to the dead weight of the soil on the screw 21. Rs is calculated. Then, the resistance Rf and the resistance Rs are subtracted from the total resistance R obtained by converting the rotary excavation torque M1, and the tip rotary excavation torque M at the target position is calculated (step S103).

  Thereafter, the computing device 5 measures the penetration depth d of the excavation blade immediately after excavation from the target position from the second and third signals from the excavator 3 that has started excavation from the target position (step S105). The control unit 51 calculates the tip rotation excavation torque M and the penetration depth d of the excavating blade at each target position with various depths as target positions.

  The control unit 51 approximates the relationship between the tip rotational excavation torque M calculated from the signal from the excavator 3 at each target position and the measured penetration depth d by the above equation (2) (step S107). In step S107, as an example, the control unit 51 uses the tip rotation excavation torque M as the vertical axis and the penetration depth d as the horizontal axis, and calculates the tip rotation excavation torque M calculated at each target position and the measured penetration depth. The points indicated by d are plotted to obtain an approximate curve represented by the equation (2).

The control unit 51 compares the coefficient term of d ² between the approximate expression obtained in step S107 and the above expression (3). Here, parameters α (angle between the excavation blade and the ground circle (deg)), β (angle between the fracture surface and the ground surface (deg)), and δ (friction angle between the soil and the blade (deg)) ) Is known, a combination of the values of the adhesive force c and the internal friction angle φ is obtained by changing other parameters. And the combination of the value of the obtained adhesive force c and the value of internal friction angle (phi) is plotted, and the approximated curve A is obtained (step S109).

  The controller 51 obtains an approximate curve B in the same manner as in step S109 by comparing the coefficient term of d between the approximate expression obtained in step S107 and the above expression (3) (step S111).

  The control unit 51 determines the value indicated by the intersection of the approximate curve A obtained in step S109 and the approximate curve B obtained in step S111 as the adhesive force c and the internal friction angle φ (step S113). The control unit 51 displays the adhesive force c and the internal friction angle φ determined in step S113 on a display device (not shown) (step S115).

<Effect of Embodiment>
In the excavator 100, the excavation resistance calculated from the state of the excavator 3 during excavation of the target soil at various depths, the measured penetration depth of the excavating blade, and the soil strength characteristic values stored in advance. The strength characteristic value of the target soil can be calculated from the model of the tip rotation excavation torque M expressed by a function of the depth of penetration of the excavating blade with the following formula as a coefficient. Therefore, unlike the conventional calculation method, it is not necessary to calculate in both the standard penetration test (first step) and earth auger excavation (second step), and the soil strength characteristic value is calculated only during earth auger excavation. can do. Therefore, it can be easily confirmed whether or not it is a support layer.

[Example]
FIG. 8 is a plot of the value of the tip rotation excavation resistance obtained by experiments by the inventors and the value of the penetration depth d (displacement) of the excavation blade. In this experiment, pure sand soil having a particle size of 2.0 mm or less and a water content of 10% was used as a sample. The excavation distance was 900 mm, and the relative density of the true sand soil was 70% for a depth of 0 to 600 mm and 100% for a depth of 600 to 900 mm. This sample was cut at a drilling speed of 10 mm / s and a rotational speed of the fixed shaft 22 of 60 r. p. m. Using the signal indicating the value of the load current applied to the motor MO during excavation from the excavator 3 when excavating with the excavator 3 with a rotation duration of 10 s, the value of the tip rotational excavation resistance and the penetration depth of the excavation blade The value of d was calculated.

The curve in FIG. 8 is an approximate curve (theoretical line) obtained from these plots. The inventors obtained the coefficient term of d ^{2 and} the coefficient term of d by applying this approximate curve to the approximate expression shown in the above formula (2). By comparing the coefficient term of d ² between the equation (2) obtained from this approximate curve and the above equation (3) and the coefficient term of d with the above equation (3), the inventors The following adhesive strength c and internal friction angle φ were obtained.
c = 25 kpa
φ = 40 degree

  From this experiment, the excavation resistance calculated from the value of the load current applied to the motor during excavation, the measured penetration depth of the excavation blade, and the formula of soil strength characteristic values stored in advance were used as coefficients. It was verified that the soil strength characteristic value can be calculated from the formula of the tip rotational excavation torque M expressed as a function of the penetration depth of the excavation blade. As a result, it was verified that only the earth auger excavation was required to obtain the strength characteristic values of these soils, and that a standard penetration test could be eliminated.

  The present invention is not limited to the above embodiment, and various modifications can be made.

DESCRIPTION OF SYMBOLS 1 Earth auger head 2 Head main body 3 Excavator 5 Arithmetic device 21 Screw 22 Fixed shaft 23 Excavation blade 23a The tip of an excavation blade 31 Drive part 51 Control part 52 Memory | storage part 53 Application 54 Input part 55 Display part 100 Excavation apparatus 511 Measurement process 512 First calculation processing 513 Second calculation processing 514 Display processing

Claims (7)

An arithmetic device electrically connected to an excavator capable of attaching an earth auger head having a drilling blade at a drilling end,
A model indicating the relationship between the strength characteristics of the soil and the excavation resistance of the excavator and the penetration depth of the soil is stored in advance,
Calculate the excavation resistance of the excavator during excavation of the target soil,
Measure the penetration depth of the excavation blade into the target soil during excavation of the target soil,
An arithmetic device that calculates the strength characteristic value of the target soil based on the excavation resistance, the penetration depth of the excavation blade, and the model. The computing device according to claim 1, wherein the strength characteristic value includes an adhesive force and an internal friction angle. The calculated excavation resistance is expressed by an approximate expression using the measured penetration depth of the excavation blade, and the coefficient of the penetration depth of the excavation blade in the approximate expression and the coefficient of the penetration depth of the excavation blade in the model The calculation device according to claim 1, wherein the strength characteristic value of the target soil is calculated by comparing The calculated excavation resistance is used for calculating the strength characteristic value except for the resistance due to the soil removal resistance and the dead weight of the earth on the screw of the earth auger head. The computing device described. An excavator capable of attaching an earth auger head having a drilling blade at a drilling end;
An excavator comprising: the arithmetic device according to any one of claims 1 to 4 electrically connected to the excavator. A method of calculating strength characteristic values of target soil excavated with an excavator equipped with an earth auger head,
Calculating excavation resistance of the excavator;
Measuring a depth of penetration of the excavation blade attached to the excavation end of the earth auger head into the target soil;
Based on the model indicating the relationship between the soil strength characteristics, the excavation resistance of the excavator and the penetration depth of the soil, and the drilling resistance and the penetration depth of the excavation blade, the strength characteristic value of the target soil is calculated. And a calculating method. A program for causing a computer to calculate strength characteristic values of target soil excavated by an excavator equipped with an earth auger head,
In the computer,
Calculating excavation resistance of the excavator;
Measuring a depth of penetration of the excavation blade attached to the excavation end of the earth auger head into the target soil;
Based on the model indicating the relationship between the soil strength characteristics, the excavation resistance of the excavator and the penetration depth of the soil, and the drilling resistance and the penetration depth of the excavation blade, the strength characteristic value of the target soil is calculated. And a step of executing the computer program.