Applicability of Propylen Glycol Solution to Tensiometer Method:Experimental Study for the Soil Moisture Measurement under Cold Condition

概要

論文の詳細を見る
In measurement of soil moisture by tensiometer under cold condition without freezing, it is necessary to fill a tensiometer with antifreeze liquid in stead of water. However, influence of using antifreeze liquid to the measured value of tensiometer has not examined enough. In this study, soil column experiments were carried out by using propylen glycol solution as antifreeze liquid, and its influence to the measured pressure head was examined. The results are summarized as follows: (1) The measurable range of pressure head with tensiometer in the case of using propylen glycol solution is narrower than that in the case of using water. The measurable range in silica sand (median diameter 0.13mm) is wider than that in Toyoura standard sand (median diameter 0.16mm). The measurable range in the case of using propylen glycol 25% solution is wider than that in the case of using 50% solution. (2) Pressure head measured with propylen glycol solution (ψPG) and that measured with water (ψW) show linear relationship as; ψW=0.90-0.97×ψPG (3) Concentration of propylen glycol solution in tensiometer decreases with time, and the decrease is larger when pressure head is low. These results suggest that propylen glycol solution can be used as a antifreeze liquid to tensiometer method in limitedrange of pressure head.
Japanese Association of Groundwater Hydrologyの論文