JP2002021059A - Automatic in-situ permeameter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically perform an in-situ permeability test accurately for filled earth and also effectively utilize the results of measurement. SOLUTION: This is an in-situ permeameter for conducting an in-situ permeability test for controlling the quality of in-situ filled earth 1 and the permeameter is provided in a water tank 12 for supplying water through a supply pipes 18 and 21 for making the water level constant at a test hole 2 formed in the filled earth 1 and the water level at the test hole 2, and water gages 10 and 14 for automatically measuring the water level in the test hole 2 and inside the water tank 12, a recorder 24 for recording the detected signals by the water gages 10 and 14 and a computer for storing and processing the water level data are provided. In addition, the water supply pipes 18 and 21 are equipped with a valve 20 for adjusting the amount of supply water by means of the detected signals by the water gage 10 of the test hole 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic in-situ permeation test apparatus, and more particularly to an automatic in-situ permeation test for controlling the quality of an embankment and a variable water permeation test automatically and in the same apparatus. The present invention relates to an automatic in-situ permeation test apparatus that can be performed with high accuracy.

[0002]

2. Description of the Related Art Conventionally, in embankment work of a fill dam, embankment such as clayey soil and soil is compacted by a compacting device such as a tamping roller and sufficiently compacted, and then as a part of quality control of the embankment. At the position, a current position permeability test of the embankment is performed.

In the in-situ permeability test, a test hole having a predetermined depth is formed in a compacted embankment, and water is injected into the test hole.
After penetrating water from the test hole into the embankment, a variable water permeability test to measure the temporal change of the water level in the test hole at a constant frequency and the amount of water permeating so as to keep the water level in the test hole constant Is supplied to the test hole, and a constant water permeability test is performed in which the amount of water supplied to the test hole in a predetermined time is measured.

Then, a permeability coefficient is calculated from the amount of water permeating at a predetermined time or the amount of water supplied to the test hole at a predetermined time to measure the permeability of the embankment so that the permeability is set to a predetermined value or less. I have.

[0005]

However, in the above-mentioned conventional in-situ permeation test, a technician has been specified for a long time of 20 hours or more in a plurality of large embankment portions for each type of embankment material. Visual measurement must be performed in units of 1 mm at regular intervals, and furthermore, since it is necessary to perform the measurement for each fixed embankment height or embankment volume, a large amount of time and labor is required and the measurement accuracy is low. In addition, separate measurement devices were installed for performing the constant water level permeability test and the variable water level permeability test. Furthermore, in organizing the data of the measurement results, there is a disadvantage that the data input operation to the computer is complicated and the productivity is low.

[0006] Therefore, the quality of the embankment can be easily controlled by being able to cope with both the constant water level method and the variable water level method of the current position permeability test method at the current position, and to improve the measurement work efficiency and the measurement accuracy. A technical problem to be solved arises in order to obtain an automatic in-situ permeation test device capable of performing the present invention, and an object of the present invention is to solve the problem.

[0007]

SUMMARY OF THE INVENTION The present invention has been proposed to achieve the above-mentioned object, and is an apparatus for performing a current-position permeability test for controlling a quality of an embankment at a current position. There is provided a test hole formed in the embankment and a water tank for supplying water through a water supply pipe in order to keep the water level of the test hole constant, and automatically measures the water level inside the test hole and the water tank. A water level meter, a recording unit for recording a detection signal from the water level meter, and a computer for storing and processing water level data, and adjusting the water supply amount to the water supply pipe according to the detection signal from the water level meter for the test hole. An automatic in-situ permeation test apparatus equipped with a valve, and an automatic in-situ permeation test apparatus provided with a breakwater pipe near the outer periphery of the water level gauge in the test hole for preventing waves on the water surface of the test hole , And the test hole or When a detection signal from the water level gauge serial aquarium is outside the initially set amount of change in the recording unit, automatic situ permeability test apparatus that emit an alarm,
Another object of the present invention is to provide an automatic in-situ permeation test apparatus provided with a differential pressure pump for supplying water from the water tank to the test hole.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to FIGS. The in-situ permeation test apparatus according to the present embodiment is used for managing the quality of the embankment 1 by the in-situ permeation test when, for example, building the core portion and the filter portion of the rock filter dam. .

As shown in FIG. 1, a cylindrical test hole 2 having a predetermined size is excavated in the embankment 1. Water is supplied to the test hole 2 from a water tank 12 via a water supply pipe 21. Further, a water level gauge 10 is provided at a central portion in the test hole 2, and the water level gauge 10 has three legs 5, 5, 5
It is vertically fixed to a gantry 4 supported by 5. The legs 5,
The bases 5 and 5 are provided with bases 6, 6 and 6 at the lower part for stable installation on the embankment 1, and the upper part is screwed to the gantry 4 and the legs 5 and 5 are provided by handles 7, 7 and 7. , 5 can be moved vertically. Then, the handles 7, 7, and 7 of the legs 5, 5, and 5 are rotated and adjusted so that the horizontal level 8 attached to the upper surface of the gantry 4 is horizontal. Further, near the outer peripheral portion of the water level gauge 10, a cylindrical wavebreak tube for preventing waves on the water surface 3 (see FIG. 2) of the test hole 2 and accurately measuring the water level with the water level gauge 10. 9 is attached to the gantry 4.

The water level gauge 10 is, for example, a magnetostrictive water level gauge, and has a sensor head supported and fixed on an upper portion of the gantry 4 and a bottom end of the test hole 2 from a lower end of the sensor head. It comprises a hanging rod-shaped stainless steel sensor main body and a float magnet 11 fitted slidably along the sensor main body. The float magnet 11 floats on the water surface 3 of the test hole 2 and changes in water level along the sensor body.
Is taken out as an electric signal based on a change in magnetostriction caused by a change in the position of the sample, and the water level is automatically measured. The electric signal is sent to a signal converter 23 installed on a support 22 to be described later via a signal cable 25 and stored in a data logger 24 as a recording unit. In addition, not only a magnetostrictive water level gauge but also an optical sensor type water level meter may be used.

On the other hand, a support 22 accommodated in a waterproof box cover 27 is installed near the test hole 2.
The support base 22 has four corners 22a, 22a, 2
2a, 22a, and a rectangular horizontal base 22b at the top
Is provided. A cylindrical water tank 12 is attached to the right side of the horizontal base 22b, and water W is stored inside.
Further, a horizontal unit 16 is provided on the upper surface of the water tank 12, and is formed so as to be adjustable with respect to the horizontal base 22b so that the water tank 12 can be installed vertically. Further, a water level gauge 14 is provided at a central portion in the water tank 12. The structure and the like of the water level gauge 14 are the same as those of the water level meter 10 provided in the test hole 2, and the description thereof will be omitted. The electric signal of the water level gauge 14 is sent to a signal converter 23 installed on the support base 22 via a signal cable 25 and stored in the data logger 24.

In the vicinity of the signal converters 23, 23,
There is provided a display device capable of confirming the position of the water surface by the water level gauges 10, 14.

Further, a differential pressure pump 1 is provided below the water tank 12.
7 is installed and the pressure is forcibly applied so that the water W can be smoothly supplied to the test hole 2. Water is supplied to the test hole 2 from the differential pressure pump 17 through a water supply pipe 18, after removing dust and the like with a dust treatment filter 19, passing through a valve 20, and disposed between the support base 22 and the gantry 4. This is performed by the water supply pipe 21. The valve 20 has a structure that can be opened and closed according to whether to execute a constant water level permeability test method or a variable water level permeability test method, which will be described later, and that the water supply amount can be adjusted.

In the upper part of the box cover 27, a signal detected by the water level gauges 10 and 14 of the test hole 2 or the water tank 12 is a unit initially set to the data logger 24 by a current position permeability test described later. A red lamp 28 is provided for lighting in an abnormal state when the amount of change per time is out of the range, and an alarm sound is emitted. Note that the abnormal state may be when rainfall or flowing water occurs.

Further, a battery 29 is used as a drive source of each device. The use of the battery 29 as a power source is easy to carry on site, does not require a power cable for each water permeability test, and can sufficiently withstand on-site use even with a small amount of stored power. is there. In the figure, reference numeral 30 denotes a connection wire to the battery 29.

Next, referring to FIG. 2, a description will be given of a constant water level permeability test method and a variable water level permeability test method. First, the constant water permeability test method will be described. First, the gantry 4 is connected to the test hole 2.
And the legs 5, 5, 5 are rotated to adjust the height so that the leveler 8 (see FIG. 1) is horizontal.
Next, the support table 22 provided with the water tank 12 and the like is provided.
(See FIG. 1) is placed on the embankment 1. And
The level gauge 16 (see FIG. 1) of the water tank 12 is adjusted to be horizontal, and the water level gauge 14 is installed vertically. Thereafter, the water level meter 10 is measured with respect to the initial water level 3 of the test hole 2.
Is set to zero, and the water level gauge 14 is also set to zero with respect to the initial water level 13 of the water tank 12 to complete the setting of the initial water level. Then, when the water W in the test hole 2 is absorbed in the embankment 1 and the water level is lowered, the valve 20 is adjusted in accordance with an instruction from the signal converter 23 so that the water W in the water tank 12 is discharged. Water is supplied into the test hole 2 via the differential pressure pump 17 and the water supply pipes 18 and 21 so that the water W in the test hole 2 is always constant.

Accordingly, the water level in the water tank 12 is measured at regular time intervals, and the water level data is stored in the data logger 24. After the measurement, the water level data stored in the data logger 24 is transferred to the personal computer 26,
The water level data is analyzed by the personal computer 26 to create a result list.

Next, a description will be given of a method of testing a variable water permeability. As in the case of the constant water level permeability test method, the installation of the gantry 4 and the support table 22 is the same, but the valve 20 is closed and the water supply from the water supply pipe 21 is stopped. Next, the water level gauge 10 is set to zero with respect to the initial water surface 3 of the test hole 2. The water W in the test hole 2 is filled with the embankment 1
Although the water level is absorbed and falls, the water level is measured at regular time intervals, and the water level data is stored in the data logger 24. After the measurement, the data is transferred to the personal computer 26 in the same manner as described above, and the water level data is analyzed by the personal computer 26 to create a result list.

In this way, it is possible to automatically and accurately measure without the need of a technician and to accumulate the measurement results in a data logger, so that the quality of the embankment can be easily managed by a personal computer.

The present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified ones.

[0021]

As described above, the invention according to claim 1 is provided in a test hole formed in the embankment and a water tank for supplying water to make the water level of the test hole constant, and the internal water level is controlled. Since a water level meter for automatic measurement, a recording unit for recording a detection signal from the water level meter, and a computer for storing and processing the water level data are provided, the water level in the test hole and in the water tank requires a great deal of labor as before. Automatic measurement without
In addition, accurate water level data can be obtained. Further, the measurement result can be read into the computer, and the productivity of the analysis of the measurement result is improved.

Further, since the water supply pipe is provided with a valve for adjusting the amount of water supply according to the detection signal from the water level meter of the test hole, the same apparatus is used to perform the water permeability test by the variable water level method or the constant water level method by adjusting the valve. be able to.

According to a second aspect of the present invention, in addition to the effect of the first aspect of the present invention, since a breakwater tube is provided near the outer peripheral portion of the water level gauge in the test hole, waves on the water surface of the test hole are prevented. Prevention and accurate water level data can be obtained.

According to a third aspect of the present invention, in addition to the effect of the first or second aspect, an alarm is issued when a detection signal from a water level meter of a test hole or a water tank is out of a range of a change amount initially set in a recording unit. Is issued, an abnormal situation can be quickly detected, and post-processing can be performed promptly.

The invention according to claim 4 is the invention according to claims 1 and 2.
Or, in addition to the effect of the third aspect, a differential pressure pump is provided to supply water from the water tank to the test hole, so that water can be supplied smoothly by forcibly applying pressure and the apparatus is made compact. be able to.

Thus, the present invention is capable of performing a constant water level permeability test and a variable water level permeability test with a single apparatus, and also has various kinds of remarkable effects such as saving labor of measurement work.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention, and is an overall perspective view of an automatic in-situ permeation test apparatus.

FIG. 2 is a configuration diagram of an automatic in-situ permeation test apparatus.

[Explanation of symbols]

 Reference Signs List 1 embankment 2 test hole 3 water surface 9 breakwater tube 10 water level gauge 12 water tank 13 water level 14 water level gauge 17 differential pressure pump 18 water supply pipe 20 valve 21 water supply pipe 23 signal converter 24 recording unit (data logger) 26 computer 28 alarm light W water

Claims (4)

[Claims] 1. An in-situ permeation test apparatus for performing an in-situ permeation test for controlling the quality of an embankment at an in-situ position, wherein a test hole formed in the embankment and a water level of the test hole are made constant. A water level meter that is provided in a water tank that supplies water through a water supply pipe to automatically measure the water level inside the test hole and the water tank, a recording unit that records a detection signal from the water level meter, and saves and processes water level data An automatic in-situ permeation test apparatus, characterized in that the water supply pipe is provided with a valve for adjusting a water supply amount according to a detection signal of the test hole by the water level gauge. 2. The automatic current position according to claim 1, wherein a wavebreak tube for preventing waves on the water surface of the test hole is provided near the outer peripheral portion of the water level gauge in the test hole. Permeability test equipment. 3. An alarm is issued when a signal detected by the water level meter of the test hole or the water tank is out of a range of a change amount initially set in the recording unit. 2. The automatic in-situ permeation test apparatus according to 2. 4. A pump according to claim 1, wherein a differential pressure pump is provided for supplying water from said water tank to said test hole.
4. The automatic in-situ permeation test apparatus according to 2 or 3.