JPH0473486B2 - - Google Patents

Description

[Detailed Description of the Invention] <<Industrial Application Field>> This invention provides a method for treating the surface layer of soft ground.
This article relates to a method for measuring the thickness of soil and its distribution.

<<Background of the Invention>> The present application has previously developed a surface treatment method using a sheet as one of the surface treatment methods for ultra-soft ground.

In this construction method, a breathable fiber sheet is laid out on the surface of ultra-soft ground, usually called sludge, in reclaimed land, reclaimed land, etc., and then high-quality soil is spread on top of it. The sheet is interposed between them.

Then, the sheet comes into close contact with the surface of the soft ground and is held by frictional resistance, dispersing and supporting the load of the disseminated earth and sand on the top, thereby causing flow failure of the ground and dispersion of the disseminated earth and sand into the ground. prevent the intrusion of

In this method, it is important to control the thickness of the soil that has been sown.

<<Problems to be solved by the invention>> Conventionally, this type of measurement method involves measuring the thickness of soil by having a worker insert a stick into the ground surface and confirming that the stick hits the top surface of the sheet. I was trying to do that. However, since this is a confirmation based on touch, etc., it often relies on the intuition and experience of the operator, making it inaccurate and time-consuming. Furthermore, it was possible to measure the thickness of only a portion of the soil, and it was not possible to determine the overall thickness distribution.

This invention has been made in view of the above problems, and it is an object of the present invention to make it possible to easily measure the thickness and its distribution with high accuracy without relying on human intuition or experience.

<<Means for Solving the Problems>> In order to achieve the above-mentioned object, the present invention provides a trolley that travels on the disseminated earth and sand, a wave transmitting section located inside the trolley with a wave transmitting surface facing underground, The present invention is characterized in that it includes a wave receiving section that receives reflected waves from a sheet buried in the surface layer of soft ground, and the thickness of the disseminated earth and sand is detected based on the time difference between the transmitted signal and the received signal.

《Operation》 The thickness of the disseminated soil can be automatically measured by using the sheet as a reflective surface and the time difference between transmitting and receiving waves.
Moreover, by moving the trolley, it is possible to know the continuous distribution state.

<<Example>> Hereinafter, an example of the measuring method of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic explanatory diagram showing the measuring method of the present invention, and FIG. 2 is a circuit block diagram showing the internal circuit of the measuring device.

In the figure, 1 is super soft ground such as sludge, 2
is high-quality earth and sand that has been sown on top of it, and an air permeable sheet 3 is buried between the earth and sand 2 and the soft ground to partition the layer of the soft ground 1 and the sown earth and sand 2.

The measuring device includes a truck 4 that travels along the upper surface of the disseminated earth and sand 2, and a laser level meter 5 that emits a laser beam toward the traveling truck 4. The laser level meter 5 is installed and fixed at an appropriate position on the ground surface of the disseminated earth and sand 2, and gives a horizontal reference value to the cart 4 by the laser it emits.

A target plate 6 is arranged on the upper part of the trolley 4,
With this target plate 6 facing the laser level meter 5, a measurer measures the thickness of the disseminated earth and sand 2 while pushing the trolley 4.

FIG. 2 shows its internal circuit configuration. Laser light from a laser oscillator 5a built into the laser level meter 5 is detected by a received light level detecting section 7 provided on the target plate 6. The output of the detection section 7 is converted into an electrical signal by a photoelectric conversion section 8 and is supplied to one input end of a subtraction section 9 .

The photoelectric conversion unit 8 outputs an electric signal according to the height of the ground surface, and its value is variable as the cart 4 moves up and down with respect to the horizontal level defined by the laser beam.

Further, inside the trolley 4, there is an oscillator 10 and a transmitter 11 that reflects the oscillation pulse output from the oscillator 10 toward the ground, and a reflected pulse output that is located underground and is reflected by the sheet 3. These output values are calculated as a time difference according to the depth from the surface by a time difference detection section 13, and the sheet 3 according to this time difference is
The depth of the installation position, that is, the thickness of the soil 2 to be sown is calculated.

The value calculated by the detection section 13 is supplied to the other input terminal of the subtraction section 9 via the amplifier 15.

The subtraction section 9 has a function of calculating the height of the cart 4 with respect to the level divided by the laser beam with the cart 4 as a reference, and the result of this calculation is output to the display section 16 and the recorder 17.

Also, inside the truck 4, there is a setting device 18 for setting the measurement start point of the truck 4, and an integrating section 19 that integrates the value according to the travel distance of the truck 4 using the position set by the setting device 18 as the starting point. is provided. The output from the integrating section 19 is displayed in parallel on the display section 16 and recorder 17.

That is, the display section 16 and the recorder 17 display or record the value of the integration section 19 on the horizontal axis and the output of the subtraction section 9 on the vertical axis.
The shape shown in the cross section of FIG. 1 is displayed and recorded.

Note that there are various means for detecting the installation thickness of the sheet 3, such as ultrasonic waves, electromagnetic waves, and magnetism. Furthermore, it goes without saying that a highly reflective substance may be provided on the surface of the sheet 3 depending on the case.

If you simply want to measure the thickness distribution, there is no need for a laser level meter or this detection means.In this case, only the thickness distribution according to the time difference between the transmitter and receiver will measure the soil surface It will be displayed or recorded as a certain level.

<<Effects of the Invention>> As explained in detail in the embodiments above, according to the method for measuring the thickness of disseminated soil according to the present invention, the thickness of disseminated soil and its distribution can be automatically determined simply by running the traveling trolley. Since it is displayed or recorded, it is possible to measure the thickness and know its distribution with much higher accuracy than conventional manual measuring means, and it is suitable as a measuring method for controlling the thickness after soil dissemination.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram showing a thickness measuring method to which the present invention is applied, and FIG. 2 is a circuit block diagram showing the electrical configuration in the same measuring method. 1... Soft ground, 2... Sown earth and sand, 3...
Sheet, 4... Traveling trolley, 11... Transmitter, 12
... Wave receiver, 13 ... Time difference detection section, 16 ... Display section, 17 ... Recorder.

Claims (1)

[Claims] 1. A trolley that travels on the soil that has been disseminated, a wave transmitting section inside the trolley with its wave transmitting surface facing underground, and a wave receiving section that receives reflected waves from a sheet buried in the surface layer of soft ground. A method for measuring the thickness of disseminated soil in a soft ground surface treatment method, characterized in that the thickness of the disseminated soil is detected based on the time difference between the transmitting signal and the receiving signal.