2002 Volume 5 Pages 777-784
The mechanical behavior of unsaturated soils strongly depends on the pore water distribution as well as the suction. The water characteristic curve (W. C. C) specifying the pore water content and the suction value plays a very important role in describing the mechanical modeling for unsaturated soils. However, the W. R. 0 shows the hysteresis loop in the wetting/drying processes. This paper emphasizes the importance of considering the hysteresis of W.C.C in the modeling. The accumulation of irreversible strains in the soil structures caused by rainfalls cannot be explained well without considering the hysteresis of W. C. C. An existing model of W. C. C is modified so as to express the accumulation of irreversible strains as the cyclic suction loading. Finally, it is shown that the modified model well explains the experimental results.