JPH0613478Y2 - Permeability meter - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] This invention is used as a backing material for a retaining wall, a concrete backing material, etc., or as a water channel or drainage channel when constructing an embankment, The present invention relates to a water permeability measuring device for so-called geotextiles such as a water-permeable sheet and a drainage sheet buried in soil, various civil engineering or building materials (herein, this is simply referred to as a civil engineering sheet, etc.).

[Conventional technology]

Conventionally, the water permeability of civil engineering sheets, etc. is measured by cutting out about 10 sheets to be measured according to the size of the water tank, stacking them in the water tank, measuring the amount of water passing through the sheet by inflowing water from above. It was evaluated. Therefore, it takes a lot of labor and time to obtain the measurement value for one sheet, and further, water leakage occurs due to the gap between the sheet and the wall of the water tank, which makes it difficult to perform accurate measurement. In addition, unlike the soil condition, it is impossible to evaluate the water permeability by applying a pressure equivalent to the soil pressure to the sheet,
In addition, the temperature conditions also changed depending on the measurement environment and were not always in line with the actual conditions. Furthermore, quantitative evaluation could not be performed on the sheet having water repellency.

[Problems to be solved by the device]

The present invention has been made in view of the above point, eliminates water leakage from the gap between the seat and the wall of the aquarium, and makes it possible to apply a pressure equivalent to earth pressure to the seat.
Let's provide a water permeability meter that can change and control the temperature of water and the environment in various ways in cold regions, hot springs, etc., and can perform measurements close to actual conditions. It is what

[Means for Solving the Problems]

The present invention is a transparent cylindrical water tank with a scale for measuring the rise of the water level, a water-permeable perforated water pressure plate that can uniformly press the sheet in this tank, and water at an arbitrary flow rate and temperature. Or a pump and a hose capable of sending the aqueous solution to the water tank, and a water level device capable of obtaining an arbitrary water pressure,
A water permeation measuring instrument, such as a civil engineering sheet, which is embedded in water or the like, is composed of a thermostatic chamber containing these components.

[Action]

According to the present invention, the end portion of the sheet is sandwiched between the upper and lower water tanks to prevent water leakage from the gap, and the sheet is uniformly pressed by the perforated water-permeable pressing plate through the spring to soil the sheet. Obtain a pressure equivalent to the pressure,
By putting all of these into a constant temperature bath having a heater and a cooler, temperature control is possible, and by making the water bath transparent, the water repellency of the sheet can be quantitatively measured as an increase in the water level.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view of the present invention. Upper and lower water tanks 3, 4
The sheet 2 is sandwiched between and held. As shown in FIG. 2, the holding portion of the sheet is provided with the sheet 2 and the perforated water-permeable pressing plate 7 between the upper and lower water tanks 3 and 4 having the collars 5 and 6, respectively. These are tightened or loosened with a tightening nut 10 on a fixed plate 11 by tightening or loosening a holding bolt 9 with a spring 8 erected on the lower collar 6, so that the space between the upper and lower flanges moves up and down along a guide 12. The sheet is then pressed at the desired pressure. Water adjusted to a constant temperature from the water tank 14 is added to the pump 17 and the pulsating shock absorber 1.
8. Pour at desired water pressure through water level 19. Water pressure is adjusted by moving the water level up and down. The entire measuring instrument and water are adjusted in advance so as to have a constant temperature.

As described above, the sheet 2 is filled with water having a constant water pressure under a desired temperature and pressure. The sheet mounted between the upper and lower water tanks is fixed with a perforated water-permeable pressing plate that is sandwiched by the pressing force of a spring corresponding to earth pressure, and water with a constant water pressure is injected onto this sheet, Measure the amount of water passing through and dripping or the time variation of the amount of water. Further, in the case of a water-repellent sheet, the maximum (limit) water level at which it starts to permeate the sheet, the time change of decreasing water level, and finally the water level remaining on the sheet are measured by the same operation. The distance between the collars is measured by the dial gauge 13, and the amount of dropped water is measured by the graduated cylinder 20 over time. Here, the number of sheets to be stacked, the tightening force of the spring, the pH of the water, the temperature, the water pressure, etc. can be adjusted to desired conditions according to the substance. Further, the pulsation of the inflow water is eliminated by providing a shock absorber between the water flow pump and the water tank.

Next, an example of data measured on a water-repellent sheet using this measuring instrument will be shown. When using a water repellent sheet, do not use a water level, and inject water directly from the pulsating flow buffer onto the sheet. Non-woven polypropylene sheets A and B having a thickness of 4 mm are used as samples, and distilled water at 20 ° C. is 100 mm / min.
Fig. 3 shows the change over time in the water level of water that was poured on the sheet at that time. The sheet pressure was set to 0. Water permeation started in the water-repellent sheet at the time when the water level increased with pouring and became 7 cm for the A sheet and 4 cm for the B sheet, and the water level did not reach 0 even after 800 seconds had elapsed. (The water injection from the pump stops when water permeation starts.) It is considered that such a difference in water level change is due to a difference in water repellency of the sheet.

[Effect of device]

As described above, the water permeability measuring instrument of the present invention prevents water leakage by eliminating the gap between the sheet and the water tank wall, and makes it possible to apply a pressure corresponding to earth pressure. The temperature control of water is realized, and the performance of water-repellent sheets can also be evaluated, and the results of water permeability can be obtained under the same measurement conditions as in the ground and soil. be able to.

[Brief description of drawings]

FIG. 1 is a schematic view of the present invention, FIG. 2 is a cross-sectional view of a seat attachment portion, and FIG. 3 is a graph showing an example of measurement data of a water repellent sheet. Description of main symbols in the drawings 1 ... Constant temperature bath, 2 ... Sheet (sample) 3 ... Water tank, 4 ... Sewer tank, 5 ... Upper brim, 6 ... Lower brim, 7 ... Perforated water-permeable press Plate 8 ... Spring, 11 ... Fixed plate 12 ... Guide, 14 ... Water tank 15 ... Heater, 16 ... Cooler 17 ... Pump, 18 ... Pulsation buffer 19 ... Water level, 20 ... … Graduated cylinder

Claims (1)

[Scope of utility model registration request] 1. A top water tank (3) and a bottom water tank (4), which are housed in a constant temperature tank (1) and are divided into upper and lower parts, and a sample (2) sandwiched between perforated water-permeable pressure plates (7). , A water tank (14) containing a heater (15) and a clerer (16), a pump (17), a pulsation shock absorber (18),
A water permeability measuring instrument having a water level device (19) and a graduated cylinder (20), in which a perforated water pressure plate (7) uniformly presses the sample (2), and the water tank (3 ) And the sewage tank (4), the distilled water with an arbitrary flow velocity and temperature is sent from the water tank (14) to the upper water tank (3) through the pump (17), and passes through the sample (2). A water permeation measuring device characterized in that the water permeation of a sample (2) is measured by measuring the amount of distilled water dropped by a graduated cylinder (20).