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| Effect of freezing and thawing process on FDR′s measuring volumetric water content of soil |
| ZHANG Ai-Li, GAO Lei |
(1.College of Art and Design, Beijing University of Technology, Beijing 100029,China; 2.School of Civil Engineering and Transportation, Hohai University, Nanjing, Jiangsu 210098, China; 3.School of Earth Sciences and Engineering, Nanjing University, Nanjing,Jiangsu 210093, China) |
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Abstract In order to study the effect of freezing and thawing process on FDR(frequency domain reflectometry)′s measuring volumetric water content of soil, the TDR-3 soil moisture sensor, based on FDR, was used to measure volumetric water content of soil at different temperatures ranged between -20-20 ℃, controlled by the temperature box in laboratory. The results show that, before freezing process above 0℃, during thawing process, the volumetric water content of soil measured by FDR increases or decreases as the temperature increases or decreases; the volumetric water content of soil, measured by FDR, decreases as temperature decreases during freezing process; and increases as temperature increases during thawing process. At the same temperature, the volumetric water content of soil measured during freezing process is higher than that measured during thawing process; at 0 ℃, the difference between them is maximal, which is significantly affected by the initial volumetric water content of soil and temperature. The results are valuable for improving the reliability of measuring the volumetric water content of soil by applying FDR in freezing and thawing process.
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Received: 06 March 2013
Published: 30 April 2013
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