JP5016900B2 - In-situ permeability test apparatus and in-situ permeability measurement system - Google Patents

Description

  The present invention, whether or not the ground layer containing a low water permeability soil material such as bentonite mixed soil and bentonite material is rolled by a heavy machine such as a vibration roller, and then the rolled ground layer has a predetermined water shielding performance. It is related with the permeability measurement technique for confirming.

  In recent years, in the water-impervious construction of water-impervious structures such as reservoirs, severe location conditions and environmental conditions that do not allow water leakage are required. In such a water-impervious construction, a low water-permeable soil material such as viscous soil, bentonite mixed soil, bentonite material, etc. is used as a raw material, and the pressure is improved by a heavy machine such as a vibrating roller to improve the water-insulating performance.

By the way, it is necessary to confirm whether or not the rolled low-permeability soil material has a predetermined water-impervious performance, and after rolling, the water-permeability for measuring the water-impervious performance of the low-permeability soil material Measuring. Such confirmation work has conventionally managed the water permeation performance by measuring the compaction density and the water permeation coefficient by a water permeation test using an RI densitometer, a sand displacement method, or several sample specimens.
JP 2003-10809 A

  However, according to the conventional technique, the water permeability is managed by the compaction density, so the water permeability coefficient is not directly obtained and confirmed, and is not a highly accurate confirmation work.

  Moreover, since the measurement of the compaction density has a small number of measurement points, only average water permeability management can be performed, and variations in water permeability due to variations in bentonite and the like cannot be predicted.

  Furthermore, when a sample specimen is obtained and a water permeability test is performed, the conventional technique has a problem that it takes about one month to half a year because of the low water permeability soil material.

  The present invention has been made in view of the above-mentioned problems, and can measure the permeability coefficient of the pressure ground layer quickly, easily and multi-pointly at the original position, and accurately satisfy the required permeability performance of the material. An object is to provide an in-situ permeability test apparatus and an in-situ permeability measurement system that can be managed.

The present invention employs the following means in order to solve the aforementioned problems.
That is, the in-situ permeability test apparatus of the present invention measures the permeability of the low-permeability soil material at the in-situ location where the ground layer is compacted after the ground layer containing the low-permeability soil material is compacted by a heavy machine. An in-situ permeability test apparatus, wherein the in-situ permeability test apparatus includes a rod part capable of penetrating into the low-permeability soil material and injecting water into the low-permeability soil material, and press-fitting water into the rod part. Press-in water injection means (water tank, recuperator, compressor) for injecting water, press-in water amount measuring means (flow meter) for measuring the press-in water amount Q to inject and inject water into the rod part, and press-in to measure time t for injecting water into the rod part Correlation between time measurement means, press-fitting speed calculating means for calculating the press-fitting speed v (= Q / t) from the press-fitting water amount Q and the press-fitting time t, and the press-fitting speed v and the permeability coefficient k in the low-permeability soil material. Pre-relevant data Memory means for because stored, based on said correlation data, the permeability coefficient calculating means for calculating a permeability k corresponding to the calculated the pressed velocity v, comprising the.

  According to this configuration, the hydraulic conductivity of the compacted ground layer can be measured quickly, easily, and in a multipoint manner, and the required hydraulic permeability of the material can be managed with high accuracy.

  And, it can be used for embankment, backfill soil, etc. that contain this low water permeability soil material (for example, clay soil, bentonite mixed soil, bentonite material, etc.), for example, low level radioactive waste shallow land disposal bentonite mixed soil It can be applied to permeability control such as backfilling soil and final disposal site impermeable layer.

  Moreover, by adjusting the press-fitting pressure, it can be applied to general soil (for example, a water-impervious zone of a dam site).

  Further, in the in-situ permeability test apparatus of the present invention, the low-permeability soil material is, for example, bentonite mixed soil, and the correlation data creates a specimen of the bentonite mixed soil in which the bentonite addition rate is changed, The structure which is the data which inject | poured water into the specimen of the said bentonite mixed soil using the said rod part and injection water injection means, and calculated | required the correlation with the injection speed v and the hydraulic conductivity k in each bentonite addition rate by the water permeability test It is good.

  Further, in the in-situ permeability test apparatus according to the present invention, the rod portion includes a cylindrical rod body having a water injection passage formed in an axial direction, and a conical bottom having a conical bottom surface fixed to one end of the rod body. A penetrating part that can penetrate into the low water permeability soil material from the tip of the cone, and the rod main body adjacent to the penetrating part is connected to the water pouring passage so that water injected into the water pouring passage can be discharged to the outside. It is good also as a structure provided with the nozzle part.

  Furthermore, the in-situ permeability measurement system of the present invention is an in-situ permeability measurement system that measures permeability at an in-situ position obtained by rolling the ground layer using an in-situ permeability test apparatus. Means for measuring position data by GPS, and control for displaying the permeability coefficient k calculated at the original position using the in-situ permeability test apparatus as a two-dimensional image based on the position data and the calculated permeability coefficient image management means for controlling the display contents to be changed for each water permeation performance on a two-dimensional image, and display means for displaying the two-dimensional image under the control of the image management means It is characterized by.

  According to this configuration, (1) multipoint measurement for a short time measurement is possible, (2) it is possible to grasp the surface water permeability performance at the original position of the construction area, (3) From the correlation data obtained in the previous water permeability test (calibration room test), the water permeability coefficient can be predicted using the results measured in the water permeability test in the field (in-situ), and variations in water permeability due to variations in bentonite, etc. Predictable.

  According to the present invention, the in-situ permeability test can measure the permeability coefficient of the rolling compaction layer in situ quickly, simply and multi-point, and can accurately manage the required permeability performance of the material. An apparatus and in-situ permeability measurement system can be provided.

  The best mode for carrying out the present invention will be exemplarily described in detail below with reference to the drawings. The in-situ permeability test apparatus according to the present embodiment uses a vibrating roller (heavy machine) to roll a ground layer containing a low-permeability soil material, and then rolls the ground-layer into a low-permeability soil material. It is a device that measures the water permeability. Further, the low water permeability soil material is bentonite mixed soil in this embodiment, and this bentonite mixed soil will be described as a case where it is used as backfill soil.

[In-situ permeability test equipment]
First, the in-situ permeability test apparatus according to the present embodiment will be described.
As shown in FIG. 1, the in-situ water permeability test apparatus 1 penetrates into bentonite mixed soil (low water permeability soil material) and injects water into the bentonite mixed soil, and press-fits water into the rod portion 2. Press-in water injection means (water tank 12, recirculator 13, compressor 14) for injecting water, press-in water amount measuring means (flow meter) 11 for measuring the amount of press-in water Q injected into the rod portion 2, and an amplifier 15 for amplifying the measured data A data logger 16 that performs arithmetic processing on the measured data and a memory card 17 that is a medium for recording the data are provided.

  The rod portion 2 and the water tank 12 are piped by, for example, a flex tube so that water in the water tank 12 can be injected through the flow meter 11. Further, the recuperator 13 and the compressor 14 are piped so as to send compressed air to the water tank 12. Further, the flow meter 11 is electrically connected to the data logger 16 via the amplifier 15.

  The rod part 2 includes a cylindrical rod body having a water injection passage in the axial direction, and a penetration part having a conical shape and having a conical bottom surface fixed to one end of the rod body and penetrating into the bentonite mixed soil from the tip of the cone. And a nozzle portion (water injection port) provided on the rod body side adjacent to the penetration portion and connected to the water injection passage and capable of discharging water injected into the water injection passage to the outside. The water injection passage of the rod body is connected to the pipe from the water tank 12 by, for example, a flex tube. The injected water is discharged radially from the nozzle portion along the circumferential direction of the rod body. In addition, the filter 3 for preventing clogging is provided in the nozzle part. Further, a donut-shaped guide 5 is used so that the rod portion 2 can penetrate vertically. Then, the doughnut-shaped weight 4 is placed on the guide 5 and fixed so that the rod portion 2 penetrating into the bentonite mixed soil does not rise or fall over at the time of water injection.

  The data logger 16 is a computer-configured device, and includes a press-fitting time measuring means (not shown) for measuring the time t for press-fitting and pouring water into the rod portion 2, a press-fitting speed v (= Q / t) is calculated based on a press-fitting speed calculating means (not shown), a storage means for obtaining and storing correlation data between the press-fitting speed v and the hydraulic conductivity k in the bentonite mixed soil, and the correlation data. A water permeability coefficient calculating means 16 for calculating the water permeability coefficient k corresponding to the press-fitting speed v and a writing means (not shown) for storing the calculated water permeability coefficient k in the memory card 17 are provided.

[Explanation of correlation data between press-fitting speed v and hydraulic conductivity k in bentonite mixed soil]
Correlation data between the press-fitting speed v and the hydraulic conductivity k in bentonite mixed soil is obtained by performing an indoor calibration test before on-site measurement.

  First, the water permeability coefficient k at each addition rate is grasped by a water permeability test (variable water level or constant water level) (FIG. 2 (a): S1).

  Next, a large number of bentonite mixed soil specimens (for example, 30 cm mold specimens) with different bentonite addition rates are prepared (FIG. 2 (a): S2). Next, the donut-shaped guide 5 is installed so that the rod portion 2 can penetrate vertically into the bentonite mixed soil specimen using the rod portion set 2, 3, 4, 5, 6 shown in FIG. 4 (a). Then, after penetrating the rod portion 2 into the specimen, the weight 4 is placed and the rod portion 2 is fixed (see FIG. 4B). Reference numeral 6 denotes a bottomed cylindrical rod top cover that can be attached to the top of the rod portion 2. When the rod portion 2 does not penetrate the specimen by human power, the rod top cover 6 is placed on the top of the rod portion 2. Is attached and is struck from above the rod top cover 6 with a rubber mallet or the like. And the press-fitting speed v in the specimen of bentonite mixed soil is acquired (FIG. 2 (a): S3).

  Next, a correlation between the hydraulic conductivity k grasped in S1 of FIG. 2A and the press-fitting speed v acquired in S3 of FIG. 2A is obtained as data shown in the graph of FIG. 3 (FIG. 2A). : S4). The obtained correlation data is stored in the storage means of the data logger 16 (see FIG. 4C).

[In-situ permeability measurement system]
Next, an in-situ permeability measurement system that measures the permeability of the compacted ground layer at the in-situ position using the in-situ permeability test apparatus 1 will be described.

  The in-situ permeability measurement system 20 is calculated using the in-situ permeability test apparatus 1 as shown in FIG. Then, control is performed to display the permeability coefficient k written in the memory card 17 as a two-dimensional image based on the position data, and the calculated permeability coefficient k is displayed on the two-dimensional image by changing display contents for each permeability performance. An image management means (not shown) for performing control, and a liquid crystal screen (display means) 21 for displaying the two-dimensional image under the control of the image management means.

  In addition, to display the display content by changing the display content for each water permeability on the two-dimensional image, a plurality of ranks for each numerical value of the water permeability coefficient k are determined in advance, and the content displayed in the display area is changed to “wavy line ( “Blue” ”,“ diagonal line (green) ”,“ crossing line (orange) ”,“ dot pattern (red) ”, etc., are determined in different shapes (colors) and displayed based on such determinations.

  The image management means is a PC device having a computer configuration, and has a central processing unit, a main memory, a keyboard as an input device, a liquid crystal screen 21 as a display means, and a hard disk device as a large-scale storage device around a bus. ing. A processing program (image management processing program) is registered together with the operating system in the hard disk device, and this image management processing program is read by the central processing unit via the main memory and sequentially executed.

  As shown in FIG. 6, the liquid permeability k is displayed on the liquid crystal screen 21 as a two-dimensional image (x-axis-y-axis screen) based on the position data. In addition, the liquid crystal screen 21 displays the calculated permeability coefficient k for each rank of the permeability coefficient k on the two-dimensional image as “wavy line (blue)”, “diagonal line (green)”, “cross line (orange)”, “dot”. It is displayed in a different shape (color) such as “pattern (red)”.

[Operation of in-situ permeability measurement system]
According to this embodiment, at the site (original position), the rod portion 2 with the nozzle portion (water injection port) is penetrated into the target ground, and the press-fitting water injection means (water tank 12, recuperator 13, compressor 14) is driven. Inject water from the water inlet. At this time, the flow meter 11 notifies the data logger 16 through the amplifier 15 of the information on the amount of injected water Q and the time t during which injection water is injected. Then, the data logger 16 calculates an injection speed (press-in speed) v (= Q / t) from the press-fit water amount Q and the press-in time t (FIG. 2B: S11). Next, the data logger 16 calculates (predicts) the water permeability coefficient k corresponding to the calculated press-fitting speed v (FIG. 2 (b): S12), and stores the calculated water permeability coefficient k in the memory card 17 by writing means. Let

Next, as shown in FIG. 5, when the water permeability coefficient k stored in the memory card 17 is transferred to a PC device having a computer configuration as image management means and the image management processing program is started, the liquid crystal screen 21 is displayed. As shown in FIG. 6, the hydraulic conductivity k is displayed in a multipoint manner as a two-dimensional image (x-axis-y-axis screen) based on the position data. In addition, the liquid crystal screen 21 displays the calculated permeability coefficient k for each rank of the permeability coefficient k on the two-dimensional image as “wavy line (blue)”, “diagonal line (green)”, “cross line (orange)”, “dot It is displayed in a different shape (color) such as “pattern (red)” (FIG. 2 (
b): S13).

  By looking at the two-dimensional image displayed on the liquid crystal screen 21, the construction worker can confirm in real time the portion where the water permeability coefficient k after rolling is varied. That is, the construction worker needs to perform re-rolling because the rolling is sufficiently performed and the water permeability is “OK” (FIG. 2B: S14), and the rolling is insufficient. b): The region of S15) can be confirmed in real time, and the required water permeability of the material can be managed with high accuracy.

  The present invention can be used for embankments, backfill soils, etc. that contain low-permeability soil materials (eg, viscous soil, bentonite mixed soil, bentonite material, etc.), for example, low-level radioactive waste shallow land disposal bentonite mixing It can be applied to water permeability performance management such as backfilling soil and final disposal site. Moreover, by adjusting the press-fitting pressure, it can be applied to general soil (for example, a water-impervious zone of a dam site).

It is the schematic of the in-situ permeability test apparatus of this invention. It is a flowchart which shows the procedure of a preliminary test and an in-situ test. It is a graph which shows the correlation with the water permeability coefficient k and the press injection speed v. It is explanatory drawing of a prior test. It is the schematic of the in-situ permeability measurement system of the present invention. It is a two-dimensional image figure of a display means.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 In-situ permeability test apparatus 2 Rod part 3 Filter 4 Weight 5 Guide 11 Pressurized water amount measuring means (flow meter)
12 Press-in water injection means (water tank)
13 Press-in water injection means (recumulator)
14 Press-in water injection means (compressor)
15 amplifier 16 data logger 17 memory card 20 in-situ permeability measurement system 21 display means (liquid crystal screen)

Claims (4)

An in-situ permeability test apparatus that measures the permeability of the low-permeability soil material at an in-situ position after rolling the ground layer by rolling the ground layer containing the low-permeability soil material by a heavy machine,
In-situ permeability test equipment
A rod portion that penetrates into the low water permeability soil material and can inject water into the low water permeability soil material;
A press-in water injection means for press-in water into the rod part;
A water injection amount measuring means for measuring a water injection amount Q to be injected into the rod portion;
A press-fitting time measuring means for measuring a time t for press-fitting water into the rod part;
A press-in speed calculating means for calculating a press-in speed v (= Q / t) from the press-in water amount Q and the press-in time t;
Storage means for preliminarily obtaining and storing correlation data between the press-fitting speed v and the water permeability coefficient k in the low water permeability soil material;
A permeability coefficient calculating means for calculating a permeability coefficient k corresponding to the calculated press-fitting speed v based on the correlation data;
Equipped with a,
The correlation data is to create a specimen having a different addition rate of the low permeability soil material, inject water into the specimen of the low permeability soil material using the rod part and press-fitting water injection means, An in-situ permeability test apparatus characterized by being data obtained by obtaining a correlation between a press-fitting speed v and a permeability coefficient k at an addition rate of a low permeability soil material . The low water permeability soil material is bentonite mixed soil,
The correlation data is to create a specimen of the bentonite mixed soil in which the bentonite addition rate is changed, and inject water into the bentonite mixed soil specimen using the rod part and press-fitting water injection means. It is the data which calculated | required the correlation with the press-fit speed v in the bentonite addition rate of this, and the hydraulic conductivity k, The in-situ permeability test apparatus of Claim 1 characterized by the above-mentioned. The rod part is
A cylindrical rod body having a water injection passage in the axial direction;
A penetrating part having a conical shape and having a conical bottom fixed to one end of the rod body and penetrating into the low water permeability soil material from a conical tip;
A nozzle portion provided on the rod body side adjacent to the penetration portion and connected to the water injection passage and capable of discharging water injected into the water injection passage to the outside;
The in-situ permeability test apparatus according to claim 1 or 2, further comprising: An in-situ permeability measurement system for measuring permeability at an in-situ position obtained by rolling the ground layer using the in-situ permeability test apparatus according to claim 1,
Means for measuring position data of the original position by GPS;
Control is performed to display the permeability coefficient k calculated at the original position using the in-situ permeability test apparatus as a two-dimensional image based on the position data, and the calculated permeability coefficient k is displayed on the two-dimensional image for each permeability performance. Image management means for controlling the display contents to be changed and displaying,
An in-situ permeability measurement system comprising: display means for displaying the two-dimensional image under the control of the image management means.

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