JPH0475355B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to an excavation ground condition detection device for use in auger excavation.More specifically, the present invention relates to an excavation ground condition detection device for use in auger excavation. This invention relates to an excavated ground condition detection device for auger excavated ground that can detect the strength of the excavated ground at the leading edge of the screw auger in the excavated ground when penetrating the foundation ground to sink and create piles. be.

(Conventional technology) Conventionally, in foundation pile driving work, in order to obtain a reliable bearing capacity for each pile to be driven, a boring survey is conducted at important points in the construction area in advance, and an underground soil columnar map is obtained from the boring survey results. Based on this soil profile map, a hypothetical foundation soil bathymetric map for the construction area is created, and based on the created hypothetical foundation soil bathymetric map, each foundation is determined based on the design load that the pile will receive. We have determined the required depth of penetration into the ground and are implementing design and construction plans.

However, the ground is not deposited in layers of a constant width, and has complex changes.

For this reason, when the foundation ground height is assumed based on the results of some boring surveys, the actual foundation ground height may differ from the assumed foundation ground height, and the piles may not be driven to the specified position and the set support In some cases, construction work was carried out without sufficient strength.

Therefore, during the foundation pile driving work, we detected the actual ground strength of the screw auger's leading edge of the excavated ground during excavation, and while confirming that it had reached the foundation ground, compared it with the ground strength at the time of design. It is necessary to quickly confirm and judge whether the supporting capacity of the piles being constructed meets the design conditions, or whether there is a need to modify or change the design or construction method.

The strength of the ground during excavation is determined by the operator reading the load current of the screw auger motor during excavation, assuming that the relationship between the load current of the screw auger motor and the ground strength is a proportional relationship. The composition of each layer of the ground and the height of the foundation ground are also confirmed based on the degree of change in the ground strength.

(Problems to be Solved by the Invention) As described above, the strength of the excavated ground and the height of the foundation ground during conventional screw auger excavation are determined by measuring the load current of the screw auger motor and using this result and other factors. Based on this information, operators used experience and intuition to judge the ground strength and foundation ground height at the time of excavation.

However, the ground strength cannot be determined only by an accurate proportional relationship with changes in the screw auger motor's load current; the screw auger's load current is affected by the excavation speed, and the harder the ground, the more the screw The measured load current of the auger motor fluctuated rapidly, making it impossible to read the load current accurately. That is, there was a problem in that a skilled judge was required to make the judgment based on this special condition.

This invention was made to solve the above-mentioned problems, and can accurately detect the ground strength, etc., and can detect the ground condition of the place where the pile will be driven, the foundation ground height, etc. without the need for a skilled judge. Anyone can clearly and easily judge whether the piles have been driven with sufficient bearing capacity according to the design reason, and it can be quickly detected during the construction stage, resulting in efficient excavation processing. It is an object of the present invention to provide an excavation ground state detection device for use in auger excavation.

(Means for Solving the Problems) In order to achieve the above-mentioned problems, the excavation ground state detection device for the auger excavation ground of the present invention has a load on the screw auger motor that rotates the screw auger that excavates the ground. Screw auger motor load current detection means that detects current at each set sampling time and outputs a screw auger motor load current signal; and a screw auger that detects the excavation distance of the cutting edge of the screw auger and outputs an excavation distance signal. The excavation distance detection means and the screw auger receive the excavation distance signal outputted from the screw auger excavation distance detection means to determine the excavation state of the cutting edge of the screw auger, and if the displacement is in the excavation direction, output an excavation determination signal. Screw auger excavation state determination detection means outputs an excavation distance set amount change signal every time the excavation distance changes by a set amount; Among the auger motor load current signals, the screw auger motor load current signal is effective for calculating the excavation ground strength at the leading edge of the auger only when the screw auger excavation state determination detection means outputs the excavation determination signal. The screw auger motor negative current information storage means sequentially temporarily stores this information, and when the screw auger excavation state judgment detection means outputs an excavation distance setting amount change signal, the previous ground strength information is used. According to the corresponding optimum average number, the screw auger motor load current information stored in the screw auger motor load current information storage means is sequentially read out in order of the latest one, and an average is calculated for the optimum average number of pieces. The screw auger motor average load current calculation means outputs the auger motor average load current information, and the screw auger excavation distance setting amount change signal outputted from the screw auger excavation state determination detection means is received, and the screw auger Screw auger cutting edge average moving speed calculating means for calculating the average moving speed when the cutting edge moves within the set amount and outputting a screw auger cutting edge average moving speed signal; and the screw auger cutting edge average moving speed calculating means. calculates the strength of the excavated ground at the leading edge of the screw auger blade in response to the screw auger blade average moving speed signal output from the screw auger blade average moving speed signal and the screw auger motor average load current information output from the screw auger motor average load current calculation means and a screw auger cutting edge top excavation ground strength calculation means for outputting the screw auger cutting edge top excavation ground strength calculation means.

(Function) The excavated ground state detection device for auger excavated ground of the present invention configured as described above detects the load of the screw auger motor that rotates the screw auger that excavates the ground by the screw auger motor load current detection means. Detecting the current at each set sampling time and outputting a screw auger motor load current signal, detecting the digging distance of the cutting edge of the screw auger by the screw auger digging distance detection means and outputting a digging distance signal, The screw auger excavation state detection means determines the excavation state of the screw auger cutting edge in response to the excavation distance signal output from the screw auger excavation distance detection means, and if the displacement is in the excavation direction, outputs an excavation judgment signal. The screw auger motor load current information storage means outputs an excavation distance set amount displacement signal every time the excavation distance changes by a set amount, and the screw auger motor load current information storage means detects the screw auger motor load current from the screw auger motor load current detection means at each set sampling time. The screw auger is effective for calculating the excavated ground strength at the leading edge of the auger only when the screw auger excavation state determination detection means outputs the excavation determination signal among the output screw auger motor load current signals. These are regarded as motor load current signals and are sequentially and temporarily stored, and are stored when the screw auger motor average load current calculation means outputs an excavation distance set amount change signal from the screw auger excavation state determination detection means. The screw auger motor load current information stored in the screw auger motor load current information storage means is sequentially read out from the screw auger motor load current information storage means according to the optimum average number corresponding to the previous ground strength information. The screw auger excavation distance set amount is calculated by averaging the average number of pieces and outputs the screw auger motor average load current information, and the screw auger cutting edge average moving speed calculation means outputs the screw auger excavation state judgment detection means. In response to the change signal, calculate the average moving speed when the screw auger's cutting edge moves within the set amount, output the screw auger cutting edge average moving speed signal, and send it to the screw auger's cutting edge top excavation ground strength calculation means. Therefore, in response to the screw auger cutting edge average moving speed signal outputted from the screw auger cutting edge average moving speed calculation means and the screw auger motor average load current information outputted from the screw auger motor average negative current calculation means, the screw The strength of the excavated ground at the beginning of the screw auger's cutting edge is calculated and the strength of the ground excavated at the beginning of the screw auger's cutting edge is output.

The strength of the ground during excavation is detected by each of the above constituent means.

(Example) Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a basic configuration block diagram of an excavated ground condition detection device for ground excavated by an auger according to an embodiment of the present invention, and FIG. It is a schematic configuration diagram when applied to a type pile driving ship.

The excavated ground state detection device for auger excavated ground according to the embodiment shown in the figure is constituted by the following respective means.

In the figure, the cutting edge 6 of a screw auger that excavates the ground 5 of the seabed 4 is rotatably driven by a turret 3 built on the deck 1a of a medium-drilling pile driving vessel 1 so as to be freely tilted by a hydraulic power unit 2. A screw auger drive unit 9 consisting of a screw auger motor 7 and a speed reducer 8 is attached so as to be able to move up and down along the guide of the leader 10 of the turret 3.

A continuous spiral screw 1 is provided around the drive shaft 8a of the reducer 8 of the screw auger drive unit 9.
1 is guided by a steady rest 13 and is formed up to the vicinity of the cutting edge 6. During auger excavation, the screw 11 is installed inside the hollow part of the steel pipe pile 12 to be driven, and when the steel pipe pile 12 is struck by a hammer (not shown), the screw 11 is inserted into the steel pipe pile 12.
A hammer is installed on the pile head of the steel pipe pile 12 that has been pulled out. Repeat this alternately as appropriate to the steel pipe pile 12.
to be poured.

At the same time as the drive shaft 8a rotates, the spiral screw 11 rotates, and the excavated earth and sand are transferred to the steel pipe pile 12.
It's starting to emit more.

Further, a measurement wire 14 is fixed to one end side of the screw auger motor 7 of the screw auger drive unit 9, and the measurement wire 14 is connected to the top sheave 15.
The measurement sheave 16 and the other sheave 17 are connected to each other so as to be tensioned and fixed to a tension weight 18.

The measurement sheave 16 has a rotary encoder 1
9 are connected to transmit the rotation of the measurement sheave 16 to the rotary encoder 19, and as the rotary encoder 19 rotates, a pulse train signal is generated.

Further, on the deck 1a of the medium-drilling pile driving vessel 1, a hanging wire is attached to the screw auger drive unit 9 so that the screw auger drive unit 9 can be moved up and down freely along the guide of the leader 10 of the turret 3. A winch 24 is mounted to fix the wire 20 and wind up the hanging wire 20 via each sheave 21, 22, 23.

26 is screw auger motor load current detection means, which includes an auger motor current detection section 27 that detects the load current of the screw auger motor 7 and outputs an analog load current signal; The A/D converter 28 converts the load current signal into a digital load current signal and outputs the same at every set sampling time (for example, every second), and outputs a screw auger motor load current signal.

29 is a screw auger digging distance detection means;
A cutting edge position detection unit 3 detects the digging distance of the cutting edge 6 based on a pulse train signal output from the rotary encoder 19 and outputs an digging distance signal.
0, and a counting section 31 that receives the excavation distance signal output from the blade edge position detection section 30 and counts the pulse signal, and outputs an excavation distance signal.

Reference numeral 32 denotes a cryo auger excavation state determination detection means, which transmits the excavation distance signal outputted from the auger excavation distance detection means 29 to an input/output control section 33 that controls the input and output of each signal and information, and a CPU 34 that controls each operation. If the cutting edge 6 is displaced in the excavation direction, the excavation determination unit 35 outputs an excavation determination signal, and the excavation distance is determined by a set amount (for example, 20
mm) and an excavation distance set amount change determination section 36 for detecting whether the excavation distance has changed by the set amount, and outputs an excavation distance set amount change signal when the screw auger's excavation distance has changed by the set amount.

Reference numeral 37 denotes screw auger motor negative current information storage means, which stores information from the screw auger motor load current detecting means 26 at every set sampling time (for example, once
The screw auger motor load current signal outputted every second) is received via the input/output control unit 33 and the CPU 34, and sampled only when the excavation determination signal is outputted by the excavation determination unit 35. The screw auger motor load current is stored sequentially.

38 is a screw auger motor average negative current calculating means, and an optimum average number determining section 39 stores an optimum average number corresponding to information on ground strength;
It consists of a root mean square calculation section 40. More specifically, the optimum average number determining unit 39 determines the ground strength threshold value (for example,
When the maximum ground strength of the construction area is 100%, the first stage is 25% or less, and the second stage is 25% to 50%.
(for example, 6 pieces if within the threshold of the first stage, 12 pieces if within the threshold of the second stage). , 24 if it is within the third stage threshold). Further, the root mean square calculation unit 40 sequentially calculates the optimum average number of screws corresponding to the previous ground strength from the screw auger motor load current information stored by the screw auger motor load current information storage means 37 in order of newest. Read out the screw auger motor load current value, subtract the no-load current value of the screw auger motor, square the subtracted values individually, take the sum of the squared individual data, and calculate the average value for the optimal average number. , calculates the square root of the value and outputs screw auger motor average negative current information.

Reference numeral 41 denotes a screw auger cutting edge average moving speed calculation means, which receives an excavation distance set amount change signal outputted from the screw auger excavation state judgment detection means 32.
When received through the CPU 34, the average moving speed of the screw auger cutting edge 6 when it moves within the set amount is calculated and a screw auger cutting edge average moving speed signal is output.

Reference numeral 42 denotes a screw auger cutting edge top excavation ground strength calculating means, which outputs the screw auger cutting edge average moving speed signal output from the screw auger cutting edge average moving speed calculating means 41 and the screw auger motor average load current calculating means 38. The screw auger motor average negative current information is received, and the ground strength is calculated by the ratio of the two signals to calculate the ground strength for excavation at the beginning of the screw auger's cutting edge, and the information on the ground strength for excavation at the beginning of the screw auger's cutting edge is output. .

Reference numeral 43 denotes an auger motor operating time accumulating unit that detects the cumulative operating time of the screw auger motor.

Reference numeral 44 denotes a setting section in which settings such as pile number, tide level, pile inclination (auger inclination), and swamping water are input.

Displays the excavation status of the screw auger, each measurement data and calculation data, operation errors, emergency accident warnings, etc., and stores and manages these results.
A screen display section 45, a printer 46, a pen recorder 47, and an external storage section 48 are each connected to the input/output control section 33.

Furthermore, a remote measurement command unit 49 that is placed at the operator's hand and issues each command is connected to the input/output control unit 3.
Connected to 3.

In the excavated ground state detection device for auger excavated ground according to the embodiment of the present invention configured as described above, an arbitrary operator starts the operation of the remote measurement command section 49, and the setting section 44 sets the pile number, tide level, etc. , pile inclination (auger inclination), and swamp data are input, excavation is started, and measurement and detection of the excavated ground condition begins.

When the measurement starts, the auger motor current detection section 27
An analog load current signal is output by
Auger motor current detection section 27 with A/D converter 28
The output analog load current signal is converted into a digital load current signal, and detected at every set sampling time (for example, every second) to output a screw auger motor load current signal.

At the same time, the movement of the measurement wire 14 is captured by the rotary encoder 19, the movement of the cutting edge 6 is converted into a pulse train signal output from the rotary encoder 19, and the cutting distance is detected by the cutting edge position detection section 30 from the pulse train signal. An excavation distance signal is output, and a counting section 31 counts the pulse signals of the excavation distance signal.

This measured signal is sent to the input/output control section 33.
The cutting edge 6 is determined by the screw auger digging distance set amount change determination unit 36 via the CPU 34, for example.
Determine whether it has moved in the digging direction by 20mm.

If the cutting edge 6 has not moved by 20 mm, the screw auger motor load current detection means 2 is activated only when the digging judgment signal is output from the digging judgment section 35.
Screw auger motor load current signals output from 6 are sequentially stored in screw auger motor load current storage means 37. In addition, when the cutting edge 6 moves by 20 mm, the screw auger motor no-load current value is sequentially determined by the optimum average number from the screw auger motor negative current information stored in the screw auger motor negative current information storage means 37 in descending order. Read out, subtract the no-load current value of the screw auger motor, square the subtracted values individually, take the sum of the squared individual data, calculate the average value for the optimal average number, and calculate the square root of that value. The screw auger motor average negative current information can then be obtained. The optimum average number at this time is the number corresponding to the previous ground strength, and when the initial ground strength has not been calculated yet, the optimum average number is set to 6, for example.

With the above configuration, the screw auger motor 7 of the screw auger drive unit 9 is driven by the winch 24.
While controlling the position, the cutting edge 6 is rotated by the rotational force of the screw auger motor 7 to excavate the ground 5, and at the appropriately excavated position, the setup is changed to a hammer and the steel pipe pile 12 is struck. By repeating these steps alternately, the steel pipe piles 12 are sunk down to the foundation ground 25.

As explained above, according to the excavated ground state detection device for auger excavated ground according to this implementation system, the greater the ground strength to be excavated, the slower the digging speed of the cutting edge 6 becomes, and the load on the screw auger motor during measurement. Even when the current fluctuates rapidly, the ground strength can be detected optimally, and the state of the ground at the tip of the ground during excavation and changes in its strength can be clearly detected.
Note that the setting unit 44 may automatically input the measured values using various measuring instruments. For example, the tide level is determined by receiving tide level data using a tide level telemeter device.
The water pressure gauge may be attached to the bottom of the ship's hull to input the water pressure value, and the pile inclination angle may be determined by attaching an inclinometer to the turret 3 and input as the pile inclination angle.

In this embodiment, when calculating the screw auger motor average negative current information, each no-load current value was squared to obtain an average value, but the calculation method is not limited to this, and any average calculation method may be used. Needless to say.

(Effects) As explained above, according to the excavated ground condition detection device for auger excavated ground of the present invention, in a construction method in which a screw auger is used to penetrate into the foundation ground to sink or create piles, etc. It is possible to accurately detect the ground strength, etc. inside the foundation, and anyone can clearly and easily judge the ground strength and foundation ground height where foundation piles will be driven, without the need for a skilled judge. It is possible to quickly confirm during the construction stage whether the piles have been driven with a reasonable sufficient bearing capacity, allowing efficient excavation processing.

[Brief explanation of the drawing]

Fig. 1 is a basic configuration block diagram of the excavated ground condition detecting device for auger excavated ground according to the present invention, and Fig. 2 shows the case where the excavated ground condition detecting device for auger excavated ground according to the present invention is applied to a medium excavation type pile driving ship. Schematic configuration diagram, 3rd
The figure is an output result diagram of a pen recorder, which is an example of the measurement results of the excavated ground state detection device for auger excavated ground according to the present invention. 6...Blade tip, 7...Screw auger motor,
26... Screw auger motor load current detection means, 29... Screw auger excavation distance detection means, 32... Screw auger excavation state determination detection means, 37... Screw auger motor load current information storage means, 38... ... Screw auger motor average load current calculation means, 41 ... Screw auger cutting edge average moving speed calculation means, 42 ... Cutting edge front excavation ground strength calculation means.

Claims (1)

[Scope of Claims] 1 Screw auger motor load current detection means for detecting the load current of the screw auger motor that rotates the screw auger that excavates the ground at every set sampling time and outputting a screw auger motor load current signal. and screw auger excavation distance detection means for detecting the excavation distance of the cutting edge of the screw auger and outputting an excavation distance signal; Screw auger excavation status determination detection means that determines the excavation status of the auger blade edge, outputs an excavation determination signal if the displacement is in the excavation direction, and outputs an excavation distance set amount change signal every time the excavation distance changes by a set amount and, among the screw auger motor load current signals output from the screw auger motor load current detecting means at each set sampling time, only when an excavation judgment signal is output by the screw auger excavation state judgment detecting means. Screw auger motor negative current information storage means for sequentially and temporarily storing the screw auger motor load current signal which is effective for calculating the excavation ground strength at the leading edge of the auger, and determining the screw auger excavation state. When the excavation distance set amount change signal is output from the detection means, the number of screws is stored by the screw auger motor load current information storage means according to the optimum average number corresponding to the previous ground strength information. Screw auger motor average load current calculation means that reads out auger motor load current information in order of newest, calculates the average by the optimum average number, and outputs screw auger motor average load current information; and the screw auger excavation state. In response to the screw auger excavation distance set amount change signal output from the determination detection means, calculate the average moving speed when the screw auger cutting edge moves within the set amount, and obtain the screw auger cutting edge average moving speed signal. a screw auger cutting edge average moving speed calculation means to output; a screw auger cutting edge average moving speed signal output from the screw auger cutting edge average moving speed calculating means; and a screw auger cutting edge average moving speed signal output from the screw auger motor average load current calculating means. Screw auger cutting edge top excavation ground strength calculating means for calculating the screw auger cutting edge top excavation ground strength by receiving the screw auger motor average load current information and outputting the screw auger cutting edge top excavation ground strength. 1. An excavation ground condition detection device for use in auger excavation.