ABSTRACT
The Soil Water Characteristic Curve (SWCC) expresses the relationship between water content and suction in a soil. It is an important relationship in unsaturated soil, and thus obtaining SWCCs experimentally is a crucial yet time consuming endeavor. Extensive research on the SWCC and its importance to unsaturated soil behavior is reported in the literature (e.g. Barbour 1998, Fredlund & Rahardjo 1993, Fredlund et al. 1996). Various test procedures and equipment have been developed to investigate the SWCC (e.g. Olson & Langfelder 1965, Fredlund & Xing 1994, Kawai et al. 2000) such as the filter paper method, pressure plate, Tempe Cell, and many others. However, it seems little research has been conducted to study the effect of sample geometry on the SWCC. Since laboratory testing generally requires significant time to generate a SWCC, there are major advantages to reducing the sample dimensions, particularly the sample height. For example, very little experimental data are available in the literature showing hysteretic behavior of the SWCC; most reported data represent a single branch of the SWCC, typically the primary drainage curve. Probably, time required for completing the SWCC test is the main reason for the lack of reported hysteretic
data; thus, reducing testing time will encourage more extensive testing to fully define hysteretic behavior of the SWCC. This was precisely the motivation for the current authors to pursue this study.
