抄録
Many of earth structures on the ground keep stability in unsaturated state. Moreover, these structures are exposed to drying and wetting conditions and changes in soil moisture always occur. Therefore, the constitutive model with unsaturated soil mechanics is needed for predicting the elasto-plastic behavior of the earth structures for a long term. The objective of this study is developing soil/water coupled F. E. analysis with unsaturated soil mechanics. In this study, the constitutive model proposed by Ohno et al. is used. Their model can express typical behavior of unsaturated soil, such as shrinkage on drying process, collapse on wetting process, and the effects of hysteresis on soil-water retention characteristic curve, and have the flexibility for dependencies on soil properties. Moreover, isoparametric element is applied on spatial discretization to preventing the dependency on mesh, which can be seen in the Akai and Tamura's method. This simulation method allows us precise prediction of the behavior of unsaturated earth structures.
