Avaliação de uma sonda TDR helicoidal para a estimativa do teor de umidade de solos em campo e laboratório / Evaluation of a helicoidal TDR probe to estimate the soil water content in laboratory and in situ

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

In this work is presented the evaluation of a recently developed helicoidal probe used for estimating the soil water content through the time domain technology (TDR). This probe has been calibrated in laboratory for different types of soils. The calibration process consisted in assessing the values of the apparent dielectric constant (Ka) and the bulk electric conductivity (ECb) of a specific soil at different levels of water content (w). Subsequently, correlations between the apparent dielectric constant and the water content have been established. The same has done with the bulk electric conductivity. Correlations between Ka and w, KA POT. 1/2and w, teta(volumetric water content) and Ka have been proposed. Also, the correlations proposed by Yu and Drnevich (2004) have been considered. To validate the proposed correlations, tests using the helicoidal probe were performed in the field. Estimated values of field water content, using the TDR technology have been compared to the correspondent oven water content values. Based on these comparisons, errors regarding the calibrations have been calculated. In the field tests, the correlations between KA POT. 1/2and w have presented more accurate results than those obtained with the other correlations. Experimental results have shown that the TDR technology for estimating water content at different depths in the field is feasible and expedite.

ASSUNTO(S)

geotechnical field tests teor de umidade constante dielétrica e condutividade elétrica volumétrica dielectric constant and electrical conductivity reflectometria no domínio do tempo time domain reflectometry water content of soils

ACESSO AO ARTIGO

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