| Title |
The Effect of Soil Water Retention Curves under Confining Stress on the Effective Stress in Variably Saturated Soils |
| Authors |
오세붕(Oh, Seboong) ; 이영휘(Lee, Young-Hu) ; 배임수(Bae, Im-Soo) ; 김상민(Kim, Sang-Min) |
| DOI |
https://doi.org/10.12652/Ksce.2012.32.4C.169 |
| Keywords |
soil water retention curves;hysteresis;confining stress;unsaturated soils;effective stress;suction stress |
| Abstract |
Soil water retention characteristics are influenced by factors of the confining stress and hysteresis in the variably saturated soil. In the description of effective stress based on hydraulic characteristics, the contribution of a matric suction to effective stress then varies with depth or is different between the processes of infiltration and evaporation. Unsaturated effective stress can be described based on suction stress characteristic curve, in which a representative soil water retention curve is required to evaluate. Pressure palate extractor tests under various confining stresses were performed and the hysteresis of drying and wetting process was also acquired. In the process of drying or wetting, a unique relationship has been estimated on the effective volumetric water content and the matric suction, which defines suction stress characteristic curve. In the unsaturated shear strength from triaxial tests, the suction stress and the effective stress were evaluated by matric suctions. The failure envelop by effective stress based on soil water retention characteristics was unique and the same as the saturated one. The measured suction stress from triaxial tests was similar to that from the soil water retention curve. Therefore it is verified that a representative soil water retention curve can be defined which is independent of the confining effect under wetting or drying process of the hysteresis. |