JP2866904B2 - Dynamic consolidation equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dynamic compaction device for compacting a ground by dropping a hammer suspended by a rope from a predetermined height.

[Conventional technology]

The method using the above-mentioned dynamic compaction apparatus is well known as one of the ground improvement methods. There are various construction management methods, such as the one disclosed in Japanese Patent Publication No. 63-265013 as an example.

Referring to FIG. 6, this conventional dynamic compaction apparatus will be described. A drum rotation detector c is provided on a wire winding drum b of a crawler crane a, and the lift of a hammer d is determined from the winding rotation amount and the rotation direction of the winding drum b. Thus, the amount of subsidence of the ground when the hammer d falls is calculated.

In addition, a hoisting operation pressure switch e and a boom angle detector f for correcting the lift are provided to detect the hammer d.

[Problems to be solved by the invention]

All the measuring means in the above-mentioned conventional dynamic consolidation apparatus are provided on the crawler crane a side, and the consolidation state due to the drop of the hammer d, such as the amount of subsidence of the ground, is calculated based on these calculated values. However, an error occurs due to the ground contact state of the crawler crane a, and even if the measurement error due to the change in the attitude of the crawler crane a is corrected by the correction means, it is not possible to perform a very accurate construction management.

Also, it is said that the acceleration of the hammer d at the time of landing has a strong correlation with the degree of improvement of the ground, and there is an example in which an acceleration sensor was attached to the hammer d, data was collected by a wired method, recorded, and analyzed. However, since the cable system is disconnected, data is not continuously taken at the working site.

The present invention is based on the above considerations, and even if the posture of a working machine body such as a crane or a tower for lifting and dropping a wire during work is changed due to land subsidence or the like, the detection data is not changed. , The construction data can be accurately controlled, the detection data can be transmitted to the receiving side without causing a transmission error, and the power supply of the transmitting unit provided on the hammer side can be reduced. It is an object of the present invention to provide a dynamic compaction device that can save money and extend the life of a battery.

[Means for solving the problem]

In order to achieve the above object, a dynamic compaction device according to the present invention is configured to compact a ground by freely dropping a hammer suspended by a chuck provided in a working machine body such as a crane so as to be vertically movable. In the dynamic compaction device, acceleration detection means for detecting acceleration acting on the hammer, land separation detection means for detecting land separation of the hammer, and acceleration data acting on the hammer by processing detection signals from these detection means. Is provided on the hammer side to transmit
An acceleration receiving unit that receives transmission data transmitted from the acceleration transmission unit and processes the transmission data is installed on the ground separated from a working machine body such as a crane.

Further, the acceleration transmission unit is provided with a memory for storing the detection data and extracting the stored detection data after a predetermined time.

Further, an arming signal circuit is used for the ground detection means.

(Operation)

According to the above configuration, the acceleration acting on the hammer when the hammer falls and the hammer ground-break are detected on the hammer side, and the data is processed and transmitted. Then, the signal is received and processed by a receiving unit installed on the ground remote from the work machine body.

The acceleration data is temporarily stored in a memory, and is transmitted after a predetermined time has elapsed, that is, after the hammer has come to a standstill.

The transmission action of the transmission unit is turned ON and OFF by the arming signal of the ground detection means.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS.

In the figure, reference numeral 1 denotes a general crawler crane.
A second winding winch 2,3 is provided. Reference numeral 4 is a tower having a tripod structure. The tower 4 is suspended and movable by, for example, a first hoisting winch 2 of the crawler crane 1 and is installed vertically near the crawler crane 1. ing. Reference numeral 5 denotes a hammer, which is connected to a chuck 7 supported by a rope mechanism 6. The chuck 7 is engaged and disengaged by hydraulic pressure. One end of the rope of the rope mechanism 6 supporting the chuck 7 is connected to the upper part of the tower 4, and the other end is connected to the second hoisting winch 3 of the crawler crane 1. The chuck 7 is raised by winding the rope.
According to this configuration, most of the load acting on the chuck 7 is supported by the tower 4. The upper end of the tower 4 is provided with a limit switch 8 for extruding the upper limit of the chuck 7.

In the support frame 5a of the hammer 5, an acceleration sensor 9 for detecting the impact acceleration of the hammer 5, an arming sensor 10 for detecting the ground breaking of the hammer 5, and a detection location of the acceleration sensor 9 are stored and transmitted wirelessly. Acceleration transmission unit
11 and a transmission antenna 12 are attached.

On the other hand, an acceleration receiving unit 13 that receives data wirelessly transmitted from the acceleration transmitting unit 11 via the transmitting antenna 12 and performs a predetermined process is installed at an appropriate place away from the crawler crane 1.

The acceleration transmission unit 11 is configured as shown in FIG. 2, wherein 14 is a CPU, 15 is an A / D converter, and 16 is a memory (RAM).
It is. The detection signal of the acceleration sensor 9 is a preamplifier.
17, input to the CPU 14 via the buffer amplifier 18. Reference numeral 19 denotes a trigger signal circuit. The trigger signal circuit 19 includes a comparator 20 and a threshold 21, and serves as a comparison circuit for determining whether the acceleration signal has reached a certain level or higher.

The signal of the arming sensor 10 is sent to the CPU 1 through an arming signal circuit 24 including a preamplifier 22 and a comparator 23.
4 is to be entered.

25 is a digital modulator and 26 is a transmitter.

The acceleration receiving unit 13 includes a receiving antenna 27, a receiver
28, a digital demodulator 29, and a buffer memory 30, which are further connected to a personal computer 32, a CRT 33, and a printer 34 via an RS232C interface 31.

A rotary encoder 35 is provided at the upper end of the tower 4 for measuring the distance from the hammer 5 to the position where the hammer 5 comes into contact with the limit switch 8 from the moving length of the rope.

 The operation of the above configuration will be described below.

The impact acceleration when the hammer 5 falls and touches the ground is detected by the acceleration sensor 9, and the detected small signal is input to the acceleration transmission unit 11, where the preamplifier
17. The signal is amplified by the buffer amplifier 18, converted into a digital signal by the A / D converter 15, and stored in the memory 16.

When the storage is completed, the power of the detection signal system connected to the acceleration sensor 9 is turned off, the power of the transmission signal system connected to the transmission antenna 12 rises (ON), and the acceleration signal stored in the memory 16 is turned off. The signal is digitally modulated by the digital modulator 24 and transmitted from the transmitter 25 by the antenna 12. All of this control is performed by the CPU 14.

The transmitted acceleration signal is received by the receiver of the acceleration receiving unit 13, demodulated by the digital demodulator 29, sequentially stored in the buffer memory 30, and transferred to the personal computer 32 by the interface 31 for data processing. And the result
It is displayed on the CRT 33 or printed out by the printer 34. At this time, since the acceleration receiving unit 13 is installed on the ground separated from the crawler crane 1 of the dynamic compaction device, the vibration of the crawler crane 1 is not applied to the acceleration receiving unit 13.

As described above, instead of transmitting the signal from the acceleration sensor 9 attached to the hammer 5 in real time, the signal is temporarily stored in the memory 16 and the radio wave environment is stabilized (the hammer 5 is grounded and stopped). Signal transmission, so there is less signal loss. Further, since the control of the acceleration transmission unit 11 is performed by the arming signal, automatic measurement is possible.

In order to automatically capture the acceleration signal, there are two types of signals: presence or absence of a signal input, and a preparation signal for receiving the signal. The former is called a trigger signal, and the latter is called an arming signal.

 The trigger signal is generated by the trigger signal circuit 19.

The arming signal is like a safety device that holds down the trigger of the gun.
The sequence does not take in data by D conversion.

The arming signal in this embodiment is obtained by changing the two strain gauges 10a and 10b attached to the column of the hammer 5.

This arming signal is generated by pulling up the hammer 5, and when the level does not reach a sufficient level and a predetermined time Δt, the CPU 14 determines the validity of the signal and ensures the arming.

FIG. 4 shows the determination of the arming and the data acquisition by the trigger signal. When the hammer 5 is cut off and the output of the comparator 23 of the arming signal circuit 24 rises, the arming is determined after a lapse of a predetermined time Δt. When arming is confirmed, the CPU 14 turns on the power to the acceleration sensor up system
Then, the over-transformer of the acceleration sensor is prepared, a signal input is waited, and a standby state is entered after 0.5 seconds. After that, the A / D converter 15 fetches data from time to time,
Continue to store in 6.

Acceleration data will become negative when the hammer 5 starts to fall, it rises instantaneously from the moment the ground t _1. At this time, a trigger signal is generated and this value is
When the level exceeds 21 levels, the captured data at this time is loaded into the memory 16, and after this loading is completed, the power supply of the amplifier system is turned off, the power supply of the transmission system is turned on, and the transmission frequency is set. Send the data in 16.
Then, after the transmission is completed, the power of the transmission system is turned off. The above operation is repeated until the dynamic consolidation ends.

In the acceleration receiving unit 13, the acceleration transmitting unit
The transmission contents from the communication unit 11 are received, and a predetermined process is performed in the data processing unit connected thereto.

At this time, in addition to the acceleration when the hammer 5 touches the ground, the penetration amount can be known from the waveform detected by the acceleration sensor 9.

That may be determined by the time from the drop beginning t ₁ to the rising ground acceleration t ₂ in FIG. 4 it is treated with the acceleration receiver unit 13.

FIG. 5 is a diagram showing the one received by the acceleration receiving unit 13.
It shows the data for each impact point, where a is acceleration, b
Indicates the amount of penetration (cumulative). S ₁ , S _2, ... Each indicate one dynamic consolidation path.

〔The invention's effect〕

According to the present invention, the acceleration detecting means for detecting the acceleration acting on the hammer 5, the ground-break detecting means for detecting the ground breaking of the hammer 5, and the detection signals from these detection signals are processed to act on the hammer 5. The acceleration transmitting unit 11 for transmitting acceleration data is provided on the hammer 5 side, so that the posture of a working machine body such as a crane or a tower for lifting and dropping the hammer 5 is temporarily reduced due to land subsidence or the like during operation. Even if it changes, the detection data is not affected by this, and accurate construction management can be performed. According to the present invention, the acceleration receiving unit for receiving and processing the transmission data transmitted from the acceleration transmission unit is installed on the ground separated from the work equipment main body such as a crane. The acceleration receiving unit is not affected by the vibration of the working machine body such as a crawler crane, and the acceleration receiving unit is not affected by the vibration caused by the work of the working machine body. Can be planned.

Further, according to the present invention, by providing the acceleration transmission unit 11 with the memory 16 for storing the detection data and extracting the stored detection data after a predetermined time has elapsed,
The detection data can be transmitted in a stable state because the hammer 5 is stationary and the vibration when the hammer 5 is settled down is suppressed, and the data transmission error can be eliminated.

In addition, by using the arming signal detection circuit as the above-mentioned ground breaking detection means, the ON / OFF of the acceleration transmission unit can be automatically performed every time the hammer 5 falls by using this arming signal. The power of the mounted battery can be saved, and the life of the battery can be prolonged.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of the present invention. FIG. 1 is an explanatory view schematically showing an apparatus for performing a dynamic compaction method, and FIG. 2 is provided on a hammer side. FIG. 3 is a block diagram showing a detection signal, FIG. 3 is a block diagram showing a receiving unit provided on the ground side,
FIG. 4 is a time chart showing a detection state of detection data,
FIG. 5 is a diagram showing a construction management waveform. FIG. 6 is a structural explanatory view showing a conventional dynamic compaction device. 1 is a crawler crane, 2 and 3 are hoisting winches, 4 is a tower, 5 is a hammer, 6 is a rope mechanism, 7 is a chuck, 9
Is an acceleration sensor, 10 is an arming sensor, 11 is an acceleration transmission unit, 12 is a transmission antenna, 13 is an acceleration reception unit, 14 is a CPU, 16 is a memory, and 24 is an arming signal circuit.

Continuing on the front page (72) Inventor Koichi Wada 4-9-1-9 Akasaka, Minato-ku, Tokyo Inside Soil Development Co., Ltd. (72) Inventor Seishiro Mizuno 4-9-1-9 Akasaka, Minato-ku, Tokyo Japan Inside Soil Development Co., Ltd. (72) Inventor Masashi Sakasaka 4-9-9, Akasaka, Minato-ku, Tokyo Japan Inside Soil Development Co., Ltd. (72) Inventor Hitoshi Fujisawa 4-9-9, Akasaka, Minato-ku, Tokyo Japan (56) References JP-A-1-256621 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) E02D 3/046

Claims (3)

(57) [Claims] In a dynamic compaction device in which a hammer suspended by a chuck provided to be vertically movable on a working machine body such as a crane is allowed to freely fall to consolidate the ground, the acceleration acting on the hammer is reduced. An acceleration detecting unit for detecting, a ground-break detecting unit for detecting a ground-break of the hammer, and an acceleration transmitting unit for processing a detection signal from these detecting units and transmitting acceleration data acting on the hammer are provided on the hammer side, A dynamic compaction device, wherein an acceleration receiving unit for receiving and processing transmission data transmitted from the acceleration transmission unit is installed on the ground separated from a work machine main body such as a crane. 2. The dynamic compaction device according to claim 1, wherein the acceleration transmitting unit is provided with a memory for storing the detection data and extracting the stored detection data after a predetermined time. 3. The dynamic consolidation device according to claim 1, wherein an arming signal circuit is used for the ground-break detection means.