| Title |
Study on the Improvement for Measuring Procedures of Volumetric Pressure Plate Extractor |
| Keywords |
unsaturated soil;matric suction;pressure plate;soil-water characteristic curve;불포화토;매트릭석션;체적압력판;함수특성곡선 |
| Abstract |
Volumetric pressure plate extractor (VPPE) can be used for measurement of the soil-water characteristic curve in the laboratory using the axis-translation technique. The volume of extracted water from the soil specimen in VPPE can be measured continuously during the test without stoppage of air pressure for the measurements. However, the water volume measurement in VPPE using an air trap, a ballast tube, a burette, and a vacuum device so as to maintain a constant pore-water pressure in the soil specimen, is quite complicated and tedious. In order to improve the measuring problems of VPPE, a modified volumetric pressure plate extractor (MVPPE) was developed and tested on residual soil specimens. In addition, the modified apparatus can measure the volume of the extracted water using both Method A and Method B of ASTMD 6836-02 depending on the range of matric suction. Measuring principles and the improvements of MVPPE and typical results obtained from the tests are discussed in the paper. |