JP7188768B2 - Support layer determination system - Google Patents

Description

Article 30, Paragraph 2 of the Patent Act applies Published in October 28, 2019, "Monthly Foundation Engineering November 2019 issue" published by General Public Works Research Institute Co., Ltd.

The present disclosure relates to a support layer determination system that acquires arbitrary data when performing excavation work and determines whether or not an excavation hole has reached a support layer of a foundation pile.

When constructing foundation piles to support a building, etc., the position of a strong support layer that can support the foundation piles by conducting a boring survey at multiple locations at appropriate intervals at the site where the foundation piles are to be installed. (depth) is being investigated.
After knowing the depth of the bearing layer by the above boring survey, the shaft is excavated at the position where the foundation pile is actually constructed, and each process such as casing erection, stabilizing liquid injection, and bottom expansion excavation. construction.

In deep strata, undulations different from those on the ground surface may occur. In other words, even the same stratum may exist at different depths at slightly different positions on the ground surface, and depending on the position where each foundation pile is installed in the bearing layer, it may exist at a depth slightly different from the result of the boring survey. .
Therefore, a technique has been developed for detecting whether or not a support layer has been reached while excavating (for example, Patent Document 1).

The support layer arrival determination device and the like disclosed in Patent Document 1 measure the current value supplied to the electric motor that rotates the excavation drill, and obtain the time integral value of the current value at predetermined time intervals. Also, a reference value acquisition depth is set at a depth shallower than the support layer, and the time integration value of the current value when excavating this reference value acquisition depth is set as the reference value.
As the excavation progressed, the time integrated value of the current value was obtained, and the obtained time integrated value was compared with the above reference value. I'm judging.
It should be noted that Patent Document 1 does not describe that the excavation drill or the like is pulled out during excavation and the earth and sand generated by the excavation work is discharged to the outside of the hole. No mention is made of the operation of lowering the drill to proceed with drilling.

JP 2018-35635 A

Conventionally, excavation work proceeds to collect soil samples that are thought to be the bearing layer, and this soil sample is compared with soil samples obtained in advance surveys to determine whether or not the bearing layer has been reached. rice field. In such a comparison of soil samples, it is difficult to identify strata with similar soil characteristics such as differences in the N value of each stratum.
That is, if a stratum having the same soil quality as the bearing layer but a different N value exists above the bearing layer at the excavation site, it becomes difficult to accurately determine whether the borehole has reached the bearing layer.
In the earth drill method, since the excavation bucket, etc. is lowered into the borehole and then pulled up repeatedly, soil and sand from other strata may be mixed when taking soil samples. You may lose track of what you have done.

The present disclosure has been made in view of the above problems, and provides a support layer determination system that determines whether or not the hole being drilled has reached the support layer when excavating using the earth drill method. offer.

A support layer determination system according to the present disclosure includes an earth drill machine having an excavation bucket that excavates a pile hole, and excavation data acquisition that is provided in the earth drill machine and generates each data while the excavation bucket is excavating. and an excavation data management unit that detects whether or not excavation by the excavation bucket has reached a support layer using the data generated by the excavation data acquisition unit, wherein the earth drill machine includes: The excavation bucket is lowered to the bottom portion of the pile hole to excavate, and when the earth and sand generated by the excavation are taken into the interior of the excavation bucket, the excavation bucket is lifted to discharge the earth and sand to the outside of the pile hole. By repeating the operation, the excavation data acquisition unit includes an encoder that detects the depth at which the excavation bucket is excavating, a torque sensor that detects the rotational torque generated in the excavation bucket during excavation, the encoder, and the A data control unit that receives each output signal of a torque sensor and generates a plurality of acquired data, and a data acquisition communication unit that transmits a plurality of acquired data generated by the data control unit to the excavation data management unit. Then, the earth drill machine lowers the excavation bucket to the bottom portion of the pile hole to start excavation, and the period until the excavation of the excavation bucket is stopped to discharge the earth and sand is one excavation. The data control unit includes a clock for measuring the time length of one excavation period, and correlates the depth indicated by the output signal of the encoder and the rotational torque indicated by the output signal of the torque sensor. generating a plurality of predetermined data for each predetermined depth, attaching the time length measured by the clock to the plurality of predetermined data, and generating the obtained data summarized for each excavation period; The acquisition communication unit sends a plurality of acquired data generated by the data control unit for each excavation period to the excavation data management unit, and the excavation data management unit transmits the plurality of acquired data input from the excavation data acquisition unit. are arranged in order of depth from the ground surface using the depths contained in the plurality of acquired data, and a characteristic curve showing the relationship between the depth and the rotational torque is obtained, and the integrated torque is obtained for each excavation period using the time length and the rotational torque included in the plurality of acquired data, and the time included in the plurality of acquired data A digging speed is obtained for each of the digging periods using the length and the depth, and a relationship between the depth and the rotational torque is obtained. Whether or not the excavation bucket has reached the support layer using the characteristic curve indicating the stability, the integrated torque obtained for each excavation, and the excavation speed obtained for each excavation period characterized by determining

Further, the excavation data management unit extracts the maximum value of the rotational torque for each excavation period from the plurality of acquired data input from the excavation data acquisition unit, and extracts the maximum value of the extracted rotational torque. and the depth, the depth at which the maximum value of the rotational torque steeply increases is extracted, and the determination is performed using the extracted depth.

Further, the excavation data management unit is characterized in that it makes the determination including the result of a boring survey performed in advance.

The data acquisition communication unit transmits the acquired data to the excavation data management unit via the communication line, the excavation data management unit includes a data management communication unit that accesses the communication line, The acquired data transmitted by the data acquisition communication unit via the communication line is received using the data management communication unit.

According to the present disclosure, it is possible to accurately determine that the drilled hole has reached the support layer.

1 is an explanatory diagram showing the configuration of an earth drilling machine provided in a support layer detection system according to an embodiment of the present disclosure; FIG. 1 is an explanatory diagram showing a schematic configuration of a support layer detection system according to an embodiment of the present disclosure; FIG. FIG. 2 is an explanatory diagram showing an example of rotational torque detected when a soft stratum is excavated by the excavating bucket of FIG. 1; FIG. 2 is an explanatory diagram showing an example of a pushing force detected when a soft stratum is excavated by the excavating bucket of FIG. 1; FIG. 2 is an explanatory diagram showing an example of rotational torque detected when a hard stratum is excavated by the excavating bucket of FIG. 1; FIG. 2 is an explanatory diagram showing an example of a pushing force detected when a hard stratum is excavated by the excavating bucket of FIG. 1; FIG. 3 is an explanatory diagram showing the operation of the support layer detection system of the present disclosure;

An embodiment of the invention will be described below.
FIG. 1 is an explanatory diagram showing the configuration of an earth drilling machine 1 provided in a support layer detection system according to an embodiment of the present disclosure.
The earth drill machine 1 has, for example, a driver's seat 12 in which a user sits and performs various operations, and a main body 10 having a traveling mechanism 11 such as a caterpillar and configured to be self-propelled.
The earth drilling machine 1 also includes a boom 13 whose base end side is supported by the rear portion of the main body 10 and which is installed so as to be able to rise and fall from the main body 10 .

A top sheave 14 for guiding a main hoisting rope (not shown) is provided at the tip of the boom 13 .
The base end side (upper end side) of the kelly bar 16 is connected to the tip of the main hoisting rope, and the base end side of the main hoisting rope is, for example, installed behind the driver's seat 12 (not shown). It is wound around the drum of the main hoisting winch. By operating the main hoisting winch, the main hoisting rope is sent out from the drum of the main hoisting winch and is wound up on the drum of the main hoisting winch. It is
That is, the kelly bar 16 to which the main hoist cable is connected is sent out from the tip of the boom 13 and pulled back to the tip of the boom 13 .
The earth drill machine 1 has an encoder 15 for detecting the feeding length of the main hoisting rope, that is, the depth of the excavating bucket 19 lowered into the excavation hole. ing.

A Kelly drive device 17 is installed on the tip side (lower end) of the Kelly bar 16 .
The Kelly drive device 17 is supported by a front frame 20 installed below the boom 13 . Further, the Kelly drive device 17 is provided with an adjustment cylinder 22 so as to adjust the positions of the Kelly drive device 17, the excavation bucket 19, and the like. Note that the adjustment cylinder 22 is, for example, installed on the Kelly drive device 17 on the front end side of the cylinder and on the lower side of the boom 13 on the base end side of the cylinder so as to move the Kelly drive device 17 in the longitudinal direction with respect to the main body 2 . is set up.
The Kelly drive device 17 has a cylinder (not shown) that pushes the Kelly bar 16 downward, and is equipped with a first pressure sensor 23 that detects the pressure generated by the cylinder.
The front frame 20 supports the Kelly drive device 17 and includes a second pressure sensor 24 for detecting the pushing force.
The Kelly drive device 17 includes a torque sensor 25 for detecting rotational torque applied to the Kelly bar 16 and the like, and a rotary table 18 is connected and fixed to the lower end side of the Kelly drive device 17 . For example, a sensor output signal transmitter 26 and the like are installed and fixed on the upper surface of the rotary table 18 .

A digging bucket 19 that is rotationally driven by a Kelly drive device 17 is installed below the rotary table 18 . The excavation bucket 19 exemplified in FIG. 1 is an enlarged-bottom bucket that forms an enlarged-bottom portion of the pile hole after excavating the shaft portion of the pile hole. The excavation bucket 19 is the above-mentioned expanded bottom bucket, a shaft digging bucket used for shaft digging, or the like (not shown), and each of the above buckets is used according to the process of excavating a pile hole.
A sensor output signal receiving unit 27 is installed behind the driver's seat 12 of the main body 10, for example, and the sensor output signal receiving unit 27 receives a wireless signal transmitted from the sensor output signal transmitting unit 26, A wiring connection is made so as to input the above received signal to an excavation data acquisition unit 30 (data control unit 40) installed in the room of the seat 12 .

The sensor output signal transmission unit 26 is configured, for example, to transmit the output signal of the torque sensor 25 by wireless communication. , the boom 13 and the like are connected to the excavation data acquisition unit 30 (data control unit 40) and the like. Each of the above sensors and the like may also be configured to input an output signal to the excavation data acquisition unit 30 (data control unit 40) through wireless communication.
In the driver's seat 12, there is provided an operating section for the user to operate the earth drill machine 1 or the like as desired. As this operation unit, for example, a display/operation unit 42 having a touch panel or the like may be provided. Here, the earth drilling machine 1 having the display/operation unit 42 will be described as an example.

FIG. 2 is an explanatory diagram showing a schematic configuration of a support layer detection system according to an embodiment of the present disclosure. The support layer detection system of FIG. It is composed of an excavation data management unit 31 that is installed.
The excavation data acquisition unit 30 includes the encoder 15, the first pressure sensor 23, the second pressure sensor 24, and the torque sensor 25 installed as described above, and a data control unit 40 that inputs the output signals of these sensors. I have. The connection between the torque sensor 25 and the data control unit 40 is such that the output signal of the torque sensor 25 is input to the data control unit 40 via the sensor output signal transmission unit 26 and the sensor output signal reception unit 27 as described above. is configured to

The excavation data acquisition unit 30 includes a memory 41 that stores each data under the control of the data control unit 40 and the aforementioned display/operation unit 42 . Under the control of the data control unit 40, the display/operation unit 42 displays, for example, switches for allowing the user to perform setting operations, etc., and displays the contents of operations input by the user's finger contact or the like to the data control unit. 40 is configured to output to.
The excavation data acquisition unit 30 accesses a communication line such as the Internet by wireless communication, and transmits and receives data to and from the outside of the earth drill machine 1 (excavation data management unit 31, etc.). A portion 43 is provided.

The excavation data management unit 31 is installed, for example, in a data center or the like provided at a location away from the excavation site, accesses the above-described communication line such as the Internet, and transmits and receives data to and from the excavation data acquisition unit 30. It is configured with a data processing unit 50 that performs analysis processing of data acquired via the management communication unit 51 and the data management communication unit 51, and stores and stores each data. The data processing unit 50 includes, for example, a storage unit that stores data and the like, a processor that performs predetermined calculations using data, a display unit that displays calculation results and the like to the user, and a display unit that allows the user to perform operations such as settings. It is an information processing device such as a personal computer provided with an operation unit and the like.
The data management communication unit 51 may be either a device that performs wireless communication or a device that performs wired communication, as long as it is configured to enable data communication with the data acquisition communication unit 43 .

Next, the operation will be explained.
In addition, the depth described below represents the depth from the surface of the earth (the depth with the upper end of the casing installed in the borehole as the origin 0).
For example, when excavating a pile hole for constructing a foundation pile using the earth drill method, the earth drill machine 1 equipped with an excavation bucket 19 (drilling bucket) for excavating the shaft excavates the shaft to a predetermined depth. After excavating up to the bottom, the casing is erected. After that, the stabilizing liquid is injected, and then the earth drilling machine 1 is used to excavate the pile hole. determine whether or not When it is determined that the support layer has been reached, the earth drilling machine 1 equipped with an enlarging bucket as the excavating bucket 19 excavates to form an enlarged bottom portion of the pile hole.

When the earth drill 1 excavates a pile hole, when a predetermined amount of earth and sand (hereinafter referred to as excavated soil) generated by excavation is taken into the excavating bucket 19, the excavating bucket 19 is pulled up to remove the excavated soil. Discharge to the outside of the pile hole. Thereafter, the excavation bucket 19, which has discharged the excavated soil, is lowered to the bottom portion of the pile hole to resume excavation.
An excavation step by the excavation bucket 19, a step of pulling up the excavation bucket 19 to discharge the excavated soil to the outside of the pile hole, and a step of lowering the excavated bucket 19, which has discharged the excavated soil, to the bottom portion of the pile hole and restarting excavation. is repeated multiple times until the desired depth is reached.

In the support layer detection system of the present disclosure, when the earth drill machine 1 operates the excavation bucket 19 to excavate a pile hole, the data control unit 40 processes the signals output from each sensor, and the excavation bucket 19 Detects whether or not the support layer has been excavated.
When the earth drill machine 1 excavates a pile hole, the encoder 15 detects the length of the main hoist rope sent out from the top sheave 14 . The data control unit 40 detects the depth reached by the kelly bar 16 and the excavation bucket 19 connected to the main hoisting rope from the output signal of the encoder 15 .
When the Kelly drive device 17 drives the excavation bucket 19 to excavate the bottom portion of the pile hole, the first pressure sensor 23 detects the pressure generated in the Kelly drive device 17 and the like, and the second pressure sensor 24 detects the thruster force generated in the front frame 20 . A torque sensor 25 installed in the Kelly drive device 17 detects rotational torque generated in the excavation bucket 19 during excavation.

The data control unit 40 inputs a signal indicating the above pressure detected by the first pressure sensor 23 and a signal indicating the above pressure detected by the second pressure sensor 24, and also inputs a signal indicating the above pressure detected by the torque sensor 25. Input a signal indicating torque.
The data control unit 40 obtains the force for pushing the excavation bucket 19 downward (into the stratum to be excavated) from the output signal of the first pressure sensor 23 and the output signal of the second pressure sensor 24, and determines the depth of the excavated pile hole and the , the pushing forces detected at each depth are associated with each other, for example, a data table is constructed and stored.
Further, the data control unit 40 obtains the rotational torque generated in the excavating bucket 19 during excavation from the output signal of the torque sensor 25, the depth of the excavated pile hole, and the rotational torque detected at each depth. are associated with each other, for example, a data table is constructed and stored.

FIG. 3 is an explanatory diagram showing an example of rotational torque detected when the excavation bucket 19 of FIG. 1 excavates a soft stratum. FIG. 4 is an explanatory diagram showing an example of the pushing force detected when excavating a soft stratum with the excavating bucket 19 of FIG.
Figures 3 and 4 show the rotational torque and pushing force detected when excavating a stratum of cohesive soil (silty clay with an N value of 6 to 8) at a depth of 15 (m) to 15.6 (m). is shown.
Since this stratum is relatively soft, the rotational torque generated in the excavating bucket 19 does not clearly change according to depth, and excavation proceeds with the torque value being relatively small.
In addition, it can be seen that in this stratum, excavation is performed with a relatively small pushing force of the excavating bucket 19 (excavation can be performed with a small pushing force).

FIG. 5 is an explanatory diagram showing an example of rotational torque detected when a hard stratum is excavated by the excavating bucket 19 of FIG. FIG. 6 is an explanatory diagram showing an example of the pushing force detected when a hard stratum is excavated by the excavating bucket 19 of FIG.
5 and 6 show the rotation torque detected when excavating a layer of sandy soil (fine sand with a conversion N value of 100) at a depth of approximately 25.4 (m) to 26.4 (m). and indentation force.
This sandy soil layer is considerably harder than the cohesive soil layer illustrated in FIGS. 3 and 4 . When excavating this sandy soil stratum, the rotational torque of the excavating bucket 19 clearly increases as the excavation progresses and the depth becomes deeper, and it can be seen that a greater rotational torque is required according to the depth. Also, it can be seen that the pushing force of the excavation bucket 19 clearly needs to be stronger as the excavation progresses and the depth becomes deeper.

It should be noted that the rotational torque and pushing force shown in FIGS. This is detected until the excavation operation of the excavation bucket 19 is stopped in order to take in the excavated soil and discharge the excavated soil to the outside of the pile hole.

FIG. 7 is an illustration showing the operation of the support layer detection system of the present disclosure. Graphs A to E shown in FIG. 7 show each value measured when excavating the same pile hole and each value obtained by data processing such as calculation, and the vertical axis of each graph is It indicates the depth of excavation.
The horizontal axis of graph A indicates the torque value (rotational torque of the excavation bucket 19) measured when a pile hole is excavated using the earth drill machine 1, and the horizontal axis of graph B indicates the pushing force. . In addition, the horizontal axis of graph C is each excavation time from when the excavation bucket 19 is lowered into the pile hole and excavation is started until the excavation is stopped to discharge the excavated soil, and graph D is the integrated torque obtained by calculation. , graph E show the Bor data (data obtained by boring survey).

As described above, the earth drill machine 1 that excavates a pile hole by the earth drill method repeatedly moves the excavation bucket 19 or the like into and out of the pile hole being excavated a plurality of times.
A graph line t in graph A indicates a rotational torque value measured every 5 (cm) of digging. Graph line a (characteristic curve showing the relationship between depth and rotational torque) is a graph line t, because the excavation bucket 19 lowered to the bottom of the pile hole starts excavation and discharges the excavated soil. The peak value of the rotational torque generated during one excavation period is extracted and the peak values of the rotational torque generated during each excavation period are connected. In graph A, the peak value of rotational torque generated during one excavation period is described as one bucket maximum torque.

Graph line b of graph E indicates the N value of each depth obtained from a boring survey conducted before starting excavation by the earth drill machine 1 .
Graph E also shows the aforementioned graph line a together with graph line b. Comparing the graph line b and the graph line a, it can be seen that the depth at which the graph line b sharply increases and the depth at which the graph line a sharply increases generally match.
When the lower stratum becomes significantly harder than the upper stratum, the N value increases steeply. That is, the possibility of reaching the support layer increases. At such a depth where the N value sharply increases, the maximum torque for one bucket also sharply increases. Further, from graph B, it can be seen that the pushing force also increases at depths where the maximum torque for one bucket increases sharply, and from graph D, it can be seen that the integrated torque also increases at that depth.

For example, when the user performs a predetermined operation on the display/operation unit 42 to operate the excavation bucket 19, the data control unit 40 detects the depth to which the excavation bucket 19 has dug from the output signal of the encoder 15 at this time. From the output signals of the first pressure sensor 23 and the second pressure sensor 24, the pushing force generated in the excavation bucket 19 during excavation is detected. Further, from the output signal of the torque sensor 25, the rotational torque generated in the excavation bucket 19 during excavation is detected.
The data control unit 40 collects the data indicating the pushing force corresponding to the detected depth and the data indicating the rotational torque corresponding to the detected depth for each excavation period described above.
The data control unit 40 has a clock (not shown) and measures the length of time during which excavation work is performed (the length of time for one excavation period) and the like. When the data on the pushing force and the data on the rotational torque are collected for each excavation period, the data control unit 40 generates acquisition data to which data indicating the time length of the excavation period is added.

The data control unit 40 generates a plurality of pieces of acquired data collected for each excavation period (for example, according to an operation performed on the display/operation unit 42), outputs the acquired data to the data acquisition communication unit 43, and outputs the acquired data to the data acquisition communication unit 43. 43 to transmit to the excavation data management unit 31 .
In addition, the data control unit 40 stores the data measured every 5 (cm) of excavation (for example, according to the operation performed on the display/operation unit 42) in the memory 41 each time, and stores the data as backup data. Save as .
That is, the data control unit 40 causes the earth drill machine 1 to operate the excavation bucket 19 lowered to the bottom of the pile hole to start excavation, stop excavation to discharge the excavated soil, and operate the excavation bucket 19. During the repetition of the operation (process) of pulling up to the ground, the acquired data collected for each excavation period is generated, stored in the memory 41, and transmitted to the excavation data management unit 31 by the data acquisition communication unit 43. conduct.

The data management communication unit 51 of the excavation data management unit 31 sequentially receives the plurality of pieces of acquired data transmitted from the excavation data acquisition unit 30 . The data management communication unit 51 inputs each received acquisition data to the data processing unit 50 .
The data processing unit 50 sequentially receives the obtained data collected for each excavation period from the data management communication unit 51, and converts the obtained data collected for each excavation period to correspond to the excavated depth. are sorted (for example, arranged in order of depth from the ground surface), and processed so that each graph shown in FIG. 7 is formed.
Specifically, for example, the maximum value of rotational torque (maximum torque value) is extracted from the acquired data collected for each excavation period, and the maximum torque values for each excavation period are arranged in correspondence with the depth. (Arranged in order of depth from the ground surface), for example, a characteristic curve showing the relationship between depth and rotational torque is obtained, and the depth at which the maximum torque value sharply increases is extracted from this characteristic curve.

The data processing unit 50, for example, extracts a depth where the maximum torque value sharply increases beyond a predetermined rate of change (a steeply increasing depth range), excavation of the pile hole ( It is determined that the excavating bucket 19) has reached the support layer.
In addition, the result of a boring survey performed in advance (for example, among the N values of each depth obtained by the boring survey, the depth where the N value increases sharply, specifically, the depth range where the N value increases sharply), and the above The extracted maximum torque value is compared with the depth (characteristic curve showing the relationship between the depth and the rotational torque) at which it sharply increases. For example, when these differences fall within a preset range, the extracted The depth at which the maximum torque value increases steeply may be determined to be the support layer. That is, for example, it may be determined whether or not the excavation bucket 19 has reached the support layer by searching for a depth at which the amount of change in each value is large.

Each piece of acquired data received by the data management communication unit 51 includes data that associates the depth with the pressing force.
The data processing unit 50 extracts the maximum value of the pushing force for each excavation period from each acquired data received by the data management communication unit 51, and extracts the pushing force during each excavation period. When the maximum force values are arranged in correspondence with the depth (arranged in order of depth from the ground surface), the depth at which the maximum pushing force value sharply increases is extracted. The extracted depth at which the maximum value of the pressing force abruptly increases is compared with the depth at which the maximum torque value abruptly increases (characteristic curve showing the relationship between depth and rotational torque). When the difference falls within a preset range, it may be determined that the excavation of the pile hole (excavation bucket 19) has reached the support layer. In addition, by comparing the depth extracted based on the maximum torque value (characteristic curve showing the relationship between depth and rotational torque) and the depth extracted based on the maximum pushing force as a result of the boring survey, For example, it may be determined whether or not the excavating bucket 19 has reached the support layer by searching for a depth at which the amount of change in each value is large.

Further, the data processing unit 50 integrates the rotation torque value detected during one excavation period and the time length of the one excavation period using each acquired data input from the data management communication unit 51, Calculate the integrated torque for each excavation period.
Specifically, the data processing unit 50 calculates the integrated torque for each excavation period from each acquired data, and converts the integrated torque to the depth (acquired data When arranging them according to the depths included in ) (arranging them in order of depth from the ground surface), the depths where the integrated torque is clearly large are extracted. The depth extracted with respect to the integrated torque in this way, the depth extracted using the maximum torque value (characteristic curve showing the relationship between depth and rotational torque), the result of boring investigation, and the maximum value of the pushing force It may be determined whether or not the excavation bucket 19 has reached the support layer by comparing the vibrations and the like extracted using the good.

The data processing unit 50 also uses the depth and the length of time of one excavation period included in the acquired data to calculate the excavation speed in the one excavation period. Specifically, this excavation speed is obtained for each acquired data, that is, it is obtained for each excavation period.
When these excavation speeds are arranged according to depth (arranged in order of depth from the ground surface), depths at which the excavation speed is obviously slow are extracted. The depth extracted with respect to the excavation speed in this way, the depth extracted using the maximum torque value (characteristic curve showing the relationship between depth and rotation torque), the result of boring survey, and the maximum value of the pushing force By comparing the depths extracted using the good.

The data processing unit 50 stores each data input from the data management communication unit 51, each depth extracted by processing as described above, each value used when extracting the depth, etc. for each pile hole They may be collectively stored and saved as a history or the like relating to construction of foundation piles.

1 Earth Drill Machine 10 Main Body 11 Traveling Mechanism Section 12 Driver's Seat 13 Boom 14 Top Sheave 15 Encoder 16 Kelly Bar 17 Kelly Drive Device 18 Rotary Table 19 Excavation Bucket 20 Front Frame 21 Thruster Cylinder 22 Adjustment Cylinder 23 First Pressure Sensor 24 Second Pressure Sensor 25 Torque sensor 26 Sensor output signal transmission unit 27 Sensor output signal reception unit 30 Excavation data acquisition unit 31 Excavation data management unit 40 Data control unit 41 Memory 42 Display/operation unit 43 Data acquisition communication unit 50 Data processing unit 51 Data management communication Department

Claims (4)

an earth drill machine having a digging bucket for drilling a pile hole;
an excavation data acquisition unit provided in the earth drill machine for generating each data when the excavation bucket is excavating;
an excavation data management unit that uses the data generated by the excavation data acquisition unit to detect whether or not excavation by the excavation bucket has reached a support layer;
with
The earth drill machine is
The excavation bucket is lowered to the bottom portion of the pile hole to excavate, and when the earth and sand generated by the excavation are taken into the interior of the excavation bucket, the excavation bucket is lifted to discharge the earth and sand to the outside of the pile hole. repeat the action
The excavation data acquisition unit
an encoder that detects the depth at which the excavation bucket is excavating;
a torque sensor that detects rotational torque generated in the excavation bucket during excavation;
a data control unit that receives output signals from the encoder and the torque sensor and generates a plurality of acquired data;
a data acquisition communication unit that transmits a plurality of acquired data generated by the data control unit to the excavation data management unit;
has
A period from when the earth drill machine lowers the excavation bucket to the bottom portion of the pile hole to start excavation to when the excavation bucket is stopped in order to discharge the earth and sand is defined as one excavation period. when
The data control unit
A clock for measuring the length of time of one excavation period;
generating a plurality of predetermined data for each predetermined depth, which associates the depth indicated by the output signal of the encoder and the rotational torque indicated by the output signal of the torque sensor;
adding the time length measured by the clock to the plurality of predetermined data to generate the obtained data summarized for each excavation period;
The data acquisition communication unit
Sending a plurality of acquired data generated by the data control unit for each excavation period to the excavation data management unit;
The excavation data management unit
The rotational torques included in the plurality of acquired data input from the excavation data acquisition unit are arranged in order of depth from the ground surface using the depths included in the plurality of acquired data, and the depth and the Obtaining a characteristic curve showing the relationship with rotational torque,
Obtaining an integrated torque for each excavation period using the time length and the rotational torque respectively included in the plurality of acquired data;
Obtaining an excavation speed for each excavation period using the time length and the depth included in the plurality of acquired data;
The excavation bucket is operated using a characteristic curve showing the relationship between the depth and the rotational torque, the integrated torque obtained for each excavation, and the excavation speed obtained for each excavation period. Determining whether the support layer has been reached,
A support layer determination system characterized by: The excavation data management unit
The maximum value of the rotational torque is extracted for each excavation period from the plurality of acquired data input from the excavation data acquisition unit, and the relationship between the extracted maximum value of the rotational torque and the depth is shown. Obtaining the characteristic curve, extracting a depth at which the maximum value of the rotational torque sharply increases, and performing the determination using the extracted depth.
The support layer determination system according to claim 1, characterized in that: The excavation data management unit
Making the determination including the results of boring surveys conducted in advance,
The support layer determination system according to claim 1 or 2, characterized in that: The data acquisition communication unit
transmitting the acquired data to the excavation data management unit via a communication line ;
The excavation data management unit
A data management communication unit that accesses the communication line,
receiving, using the data management communication unit, the obtained data transmitted by the data acquisition communication unit via the communication line;
The support layer determination system according to any one of claims 1 to 3, characterized in that:

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