ISSN: 1945-7545
CODEN: GTJODJ
Page Count: 5

A Dynamic Method for Determining the Soil Water Characteristic Curve for Coarse-Grained Soils

Rassam, DW
Environmental modeling engineer, Department of Natural Resources, Resource Science Centre, Brisbane,

Williams, DJ
Associate professor of geomechanics, University of Queensland, Brisbane,

(Received 16 July 1998; accepted 5 August 1999)

Abstract

The air-entry suction is an extremely important parameter in the water characteristic curve, but is difficult to identify when using conventional static methods such as the pressure plate apparatus. In the dynamic method described herein, instantaneous measurement of matric suction and water content are acquired from a soil specimen undergoing a slow drying cycle with the aid of a tensiometer and a soil moisture probe, respectively. The method offers a quick and reliable way of quantifying the drying soil-water characteristic curve (SWCC) for matric suctions of up to 80 kPa. The large number of data points acquired make it easy to obtain an accurate estimate of the air-entry suction. It is particularly effective for soils ranging from medium sands to sandy silts where a nearly continuous SWCC is provided.

Keywords:
air-entry suction (AES), matric suction, soil-water characteristic curve (SWCC), soil-moisture probe, tensiometer, unsaturated soils, volumetric water content

Paper ID: GTJ11124J
DOI: 10.1520/GTJ11124J
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